Monitor/GPU/Connection Combinations

This is a collection of combinations which are known to work. Please comment below with your information so that we can hopefully find a pattern for when a longer delay is needed.

GPU
Display
Connection
minReplyDelay

AMD Vega 64
LG 38UC99-W
DisplayPort
20 ms

AMD Radeon Pro 460
LG 38UC99-W
USB-C
20 ms

Intel HD Graphics 4000
LG 38UC99-W
DisplayPort
default

Intel HD Graphics 4000
LG 38UC99-W
HDMI
reading doesn't work at all

GPU
Display
Connection
minReplyDelay

Intel Iris 1536 MB
LG 34UC88-B
DisplayPort
reading doesn't work at all

Intel Iris 1536 MB
LG 34UC88-B
HDMI
reading doesn't work at all

More Details

Using 20 ms freezes the system.
MacBook Pro (Retina, 13-inch, late 2013)

Logs (from DisplayPort, default minReplyDelay, 100 tries, c8608b1)
2019-05-09 19:34:58.626544+0200 MonitorControl[19792:1552617] Framebuffer: AppleIntelFramebuffer
2019-05-09 19:34:58.626637+0200 MonitorControl[19792:1552617] Location: IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/IGPU@2/AppleIntelFramebuffer@1/display0/AppleDisplay
2019-05-09 19:34:58.626693+0200 MonitorControl[19792:1552617] Vendor ID: 7789, Product ID: 30436, Serial Number: 451657
2019-05-09 19:34:58.626781+0200 MonitorControl[19792:1552617] Unit Number: 1
2019-05-09 19:34:58.626804+0200 MonitorControl[19792:1552617] Service Port: 80495
2019-05-09 19:34:58.627551+0200 MonitorControl[19792:1552617] kIOI2CSimpleTransactionType is supported.
2019-05-09 19:34:58.631024+0200 MonitorControl[19792:1552617] Framebuffer: AppleIntelFramebuffer
2019-05-09 19:34:58.631083+0200 MonitorControl[19792:1552617] Location: IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/IGPU@2/AppleIntelFramebuffer@1/display0/AppleDisplay
2019-05-09 19:34:58.631127+0200 MonitorControl[19792:1552617] Vendor ID: 7789, Product ID: 30436, Serial Number: 451657
2019-05-09 19:34:58.631195+0200 MonitorControl[19792:1552617] Unit Number: 1
2019-05-09 19:34:58.683315+0200 MonitorControl[19792:1552617] Service Port: 80495
2019-05-09 19:34:58.688084+0200 MonitorControl[19792:1552617] The following supported displays were found:
2019-05-09 19:34:58.691580+0200 MonitorControl[19792:1552617]  - LG ULTRAWIDE (Vendor: 7789, Model: 30436)
2019-05-09 19:34:58.694896+0200 MonitorControl[19792:1552617] Framebuffer: AppleIntelFramebuffer
2019-05-09 19:34:58.694941+0200 MonitorControl[19792:1552617] Location: IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/IGPU@2/AppleIntelFramebuffer@1/display0/AppleDisplay
2019-05-09 19:34:58.694962+0200 MonitorControl[19792:1552617] Vendor ID: 7789, Product ID: 30436, Serial Number: 451657
2019-05-09 19:34:58.695031+0200 MonitorControl[19792:1552617] Unit Number: 1
2019-05-09 19:34:58.695051+0200 MonitorControl[19792:1552617] Service Port: 80495
2019-05-09 19:34:58.695738+0200 MonitorControl[19792:1552617] kIOI2CSimpleTransactionType is supported.
2019-05-09 19:34:58.702438+0200 MonitorControl[19792:1552617] Framebuffer: AppleIntelFramebuffer
2019-05-09 19:34:58.702489+0200 MonitorControl[19792:1552617] Location: IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/IGPU@2/AppleIntelFramebuffer@1/display0/AppleDisplay
2019-05-09 19:34:58.702514+0200 MonitorControl[19792:1552617] Vendor ID: 7789, Product ID: 30436, Serial Number: 451657
2019-05-09 19:34:58.702571+0200 MonitorControl[19792:1552617] Unit Number: 1
2019-05-09 19:34:58.702589+0200 MonitorControl[19792:1552617] Service Port: 80495
2019-05-09 19:34:58.708528+0200 MonitorControl[19792:1552617] Framebuffer: AppleIntelFramebuffer
2019-05-09 19:34:58.708575+0200 MonitorControl[19792:1552617] Location: IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/IGPU@2/AppleIntelFramebuffer@1/display0/AppleDisplay
2019-05-09 19:34:58.708598+0200 MonitorControl[19792:1552617] Vendor ID: 7789, Product ID: 30436, Serial Number: 451657
2019-05-09 19:34:58.708654+0200 MonitorControl[19792:1552617] Unit Number: 1
2019-05-09 19:34:58.708671+0200 MonitorControl[19792:1552617] Service Port: 80495
2019-05-09 19:34:58.709289+0200 MonitorControl[19792:1552617] kIOI2CSimpleTransactionType is supported.
2019-05-09 19:34:58.807276+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 94.
2019-05-09 19:34:58.957974+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 83.
2019-05-09 19:34:58.993124+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 109.
2019-05-09 19:34:59.193169+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 111.
2019-05-09 19:34:59.224544+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 1.
2019-05-09 19:34:59.489957+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 55, got 99.
2019-05-09 19:34:59.506710+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 62.
2019-05-09 19:34:59.674795+0200 MonitorControl[19792:1552779] Failed to send request to interface 0 for framebuffer with ID 80495.
2019-05-09 19:34:59.689704+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 30.
2019-05-09 19:34:59.974786+0200 MonitorControl[19792:1552773] Failed to send request to interface 0 for framebuffer with ID 80495.
2019-05-09 19:34:59.989794+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 75.
2019-05-09 19:35:00.288866+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 2, got 101.
2019-05-09 19:35:00.304793+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 56.
2019-05-09 19:35:00.423079+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 73.
2019-05-09 19:35:00.439145+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 83.
2019-05-09 19:35:00.639920+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 3, got 82.
2019-05-09 19:35:00.656419+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 94.
2019-05-09 19:35:00.937797+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 95.
2019-05-09 19:35:00.952091+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 112.
2019-05-09 19:35:01.223309+0200 MonitorControl[19792:1552773] Failed to send request to interface 0 for framebuffer with ID 80495.
2019-05-09 19:35:01.239088+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 109.
2019-05-09 19:35:01.388071+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 1.
2019-05-09 19:35:01.404001+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 32, got 55.
2019-05-09 19:35:01.623394+0200 MonitorControl[19792:1552773] Failed to send request to interface 0 for framebuffer with ID 80495.
2019-05-09 19:35:01.637754+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 28, got 126.
2019-05-09 19:35:01.938763+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 3, got 66.
2019-05-09 19:35:01.954400+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 113.
2019-05-09 19:35:02.239219+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 92.
2019-05-09 19:35:02.254785+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 80.
2019-05-09 19:35:02.539643+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 95.
2019-05-09 19:35:02.555644+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 106.
2019-05-09 19:35:02.839437+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 59.
2019-05-09 19:35:02.855644+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 108.
2019-05-09 19:35:03.139475+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 46, got 39.
2019-05-09 19:35:03.154732+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 94.
2019-05-09 19:35:03.338823+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 37.
2019-05-09 19:35:03.354021+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 73.
2019-05-09 19:35:03.638498+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 8, got 48.
2019-05-09 19:35:03.654467+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 126.
2019-05-09 19:35:03.938660+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 68.
2019-05-09 19:35:03.953871+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 114.
2019-05-09 19:35:04.223510+0200 MonitorControl[19792:1552773] Failed to send request to interface 0 for framebuffer with ID 80495.
2019-05-09 19:35:04.238566+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 1, got 95.
2019-05-09 19:35:04.538535+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 2, got 81.
2019-05-09 19:35:04.553645+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 125.
2019-05-09 19:35:04.838425+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 111.
2019-05-09 19:35:04.853635+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 15, got 14.
2019-05-09 19:35:05.138390+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 55.
2019-05-09 19:35:05.153835+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 32, got 80.
2019-05-09 19:35:05.338248+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 112, got 0.
2019-05-09 19:35:05.353498+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 3, got 115.
2019-05-09 19:35:05.588044+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 66.
2019-05-09 19:35:05.603269+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 77.
2019-05-09 19:35:05.873435+0200 MonitorControl[19792:1552773] Failed to send request to interface 0 for framebuffer with ID 80495.
2019-05-09 19:35:05.888371+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 94.
2019-05-09 19:35:06.173450+0200 MonitorControl[19792:1552773] Failed to send request to interface 0 for framebuffer with ID 80495.
2019-05-09 19:35:06.188968+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 101.
2019-05-09 19:35:06.387836+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 26.
2019-05-09 19:35:06.403487+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 70.
2019-05-09 19:35:06.624085+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 64, got 99.
2019-05-09 19:35:06.639608+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 46, got 94.
2019-05-09 19:35:06.738740+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 3, got 37.
2019-05-09 19:35:06.753911+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 125.
2019-05-09 19:35:07.039103+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 7.
2019-05-09 19:35:07.054885+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 16, got 102.
2019-05-09 19:35:07.323443+0200 MonitorControl[19792:1552779] Failed to send request to interface 0 for framebuffer with ID 80495.
2019-05-09 19:35:07.338777+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 71.
2019-05-09 19:35:07.639220+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 2, got 112.
2019-05-09 19:35:07.656132+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 92.
2019-05-09 19:35:07.880612+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 1, got 81.
2019-05-09 19:35:07.897107+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 16, got 95.
2019-05-09 19:35:08.173552+0200 MonitorControl[19792:1552773] Failed to send request to interface 0 for framebuffer with ID 80495.
2019-05-09 19:35:08.188274+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 106.
2019-05-09 19:35:08.489551+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 59.
2019-05-09 19:35:08.504603+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 2, got 56.
2019-05-09 19:35:08.773605+0200 MonitorControl[19792:1552773] Failed to send request to interface 0 for framebuffer with ID 80495.
2019-05-09 19:35:08.789229+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 32, got 114.
2019-05-09 19:35:08.989933+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 14, got 10.
2019-05-09 19:35:09.008458+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 39.
2019-05-09 19:35:09.288660+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 3, got 82.
2019-05-09 19:35:09.304260+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 94.
2019-05-09 19:35:09.588103+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 95.
2019-05-09 19:35:09.603594+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 96.
2019-05-09 19:35:09.889075+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 109.
2019-05-09 19:35:09.906699+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 1.
2019-05-09 19:35:10.143168+0200 MonitorControl[19792:1552779] Failed to send request to interface 0 for framebuffer with ID 80495.
2019-05-09 19:35:10.157532+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 84.
2019-05-09 19:35:10.440226+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 32, got 62.
2019-05-09 19:35:10.456091+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 53, got 62.
2019-05-09 19:35:10.738577+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 94.
2019-05-09 19:35:10.755184+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 71.
2019-05-09 19:35:11.039433+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 22.
2019-05-09 19:35:11.056427+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 103.
2019-05-09 19:35:11.239053+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 83.
2019-05-09 19:35:11.255014+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 16, got 81.
2019-05-09 19:35:11.342694+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 77.
2019-05-09 19:35:11.377921+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 2, got 92.
2019-05-09 19:35:11.638763+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 7, got 114.
2019-05-09 19:35:11.654034+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 26.
2019-05-09 19:35:11.923616+0200 MonitorControl[19792:1552773] Failed to send request to interface 0 for framebuffer with ID 80495.
2019-05-09 19:35:11.940498+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 110, got 70.
2019-05-09 19:35:12.238491+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 32, got 110.
2019-05-09 19:35:12.253741+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 112, got 90.
2019-05-09 19:35:12.538544+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 9.
2019-05-09 19:35:12.554579+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 114.
2019-05-09 19:35:12.723970+0200 MonitorControl[19792:1552779] Failed to send request to interface 0 for framebuffer with ID 80495.
2019-05-09 19:35:12.738930+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 1, got 95.
2019-05-09 19:35:13.040371+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 2, got 81.
2019-05-09 19:35:13.056026+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 109.
2019-05-09 19:35:13.323789+0200 MonitorControl[19792:1552773] Failed to send request to interface 0 for framebuffer with ID 80495.
2019-05-09 19:35:13.338806+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 111.
2019-05-09 19:35:13.638588+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 15, got 14.
2019-05-09 19:35:13.653925+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 99.
2019-05-09 19:35:13.846881+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 9.
2019-05-09 19:35:13.873695+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 30.
2019-05-09 19:35:14.093246+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 46, got 101.
2019-05-09 19:35:14.108711+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 101.
2019-05-09 19:35:14.388199+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 58.
2019-05-09 19:35:14.402811+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 73.
2019-05-09 19:35:14.688848+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 32, got 115.
2019-05-09 19:35:14.703701+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 82.
2019-05-09 19:35:14.989031+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 3, got 94.
2019-05-09 19:35:15.005748+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 15, got 80.
2019-05-09 19:35:15.288687+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 2, got 114.
2019-05-09 19:35:15.304163+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 109.
2019-05-09 19:35:15.573903+0200 MonitorControl[19792:1552773] Failed to send request to interface 0 for framebuffer with ID 80495.
2019-05-09 19:35:15.588955+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 1.
2019-05-09 19:35:15.889082+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 32, got 23.
2019-05-09 19:35:15.923575+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 14, got 80.
2019-05-09 19:35:16.189001+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 224, got 190.
2019-05-09 19:35:16.204152+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 2, got 112.
2019-05-09 19:35:16.488879+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 92.
2019-05-09 19:35:16.504022+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 1, got 81.
2019-05-09 19:35:16.739933+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 95.
2019-05-09 19:35:16.756177+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 106.
2019-05-09 19:35:17.039793+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 59.
2019-05-09 19:35:17.056019+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 4, got 104.
2019-05-09 19:35:17.339642+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 39.
2019-05-09 19:35:17.356055+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 112.
2019-05-09 19:35:17.538721+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 3, got 38.
2019-05-09 19:35:17.554985+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 55, got 126.
2019-05-09 19:35:17.838936+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 48.
2019-05-09 19:35:17.854283+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 118.
2019-05-09 19:35:18.139330+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 68.
2019-05-09 19:35:18.155381+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 3, got 113.
2019-05-09 19:35:18.438685+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 95.
2019-05-09 19:35:18.454477+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 80.
2019-05-09 19:35:18.739281+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 48, got 79.
2019-05-09 19:35:18.756537+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 53, got 90.
2019-05-09 19:35:19.038828+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 14.
2019-05-09 19:35:19.054470+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 56.
2019-05-09 19:35:19.339248+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 32, got 112.
2019-05-09 19:35:19.356886+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 56, got 24.
2019-05-09 19:35:19.638181+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 3.
2019-05-09 19:35:19.653746+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 16, got 81.
2019-05-09 19:35:19.938026+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 77.
2019-05-09 19:35:19.954139+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 2, got 92.
2019-05-09 19:35:20.239690+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 7, got 98.
2019-05-09 19:35:20.255827+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 26.
2019-05-09 19:35:20.539047+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 70.
2019-05-09 19:35:20.554664+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 99.
2019-05-09 19:35:20.838629+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 30.
2019-05-09 19:35:20.854718+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 11.
2019-05-09 19:35:21.139581+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 126.
2019-05-09 19:35:21.155824+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 96, got 103.
2019-05-09 19:35:21.439523+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 102.
2019-05-09 19:35:21.456242+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 87.
2019-05-09 19:35:21.740105+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 112.
2019-05-09 19:35:21.755503+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 28, got 66.
2019-05-09 19:35:22.023834+0200 MonitorControl[19792:1552773] Failed to send request to interface 0 for framebuffer with ID 80495.
2019-05-09 19:35:22.038980+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 81.
2019-05-09 19:35:22.239880+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 94.
2019-05-09 19:35:22.256041+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 15, got 117.
2019-05-09 19:35:22.539688+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 46, got 21.
2019-05-09 19:35:22.556907+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 190, got 134.
2019-05-09 19:35:22.840179+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 32, got 80.
2019-05-09 19:35:22.855603+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 224, got 202.
2019-05-09 19:35:23.140577+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 32, got 9.
2019-05-09 19:35:23.155720+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 82.
2019-05-09 19:35:23.439327+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 3, got 94.
2019-05-09 19:35:23.455485+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 15, got 80.
2019-05-09 19:35:23.725292+0200 MonitorControl[19792:1552773] Failed to send request to interface 0 for framebuffer with ID 80495.
2019-05-09 19:35:23.740674+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 2, got 98.
2019-05-09 19:35:24.041077+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 109.
2019-05-09 19:35:24.056469+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 1.
2019-05-09 19:35:24.341086+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 84.
2019-05-09 19:35:24.356415+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 62.
2019-05-09 19:35:24.640665+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 30.
2019-05-09 19:35:24.656433+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 32, got 75.
2019-05-09 19:35:24.941390+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 71.
2019-05-09 19:35:24.957602+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 46, got 56.
2019-05-09 19:35:25.241201+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 103.
2019-05-09 19:35:25.257530+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 83.
2019-05-09 19:35:25.540774+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 81.
2019-05-09 19:35:25.556681+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 3, got 94.
2019-05-09 19:35:25.841042+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 0, got 92.
2019-05-09 19:35:25.856584+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 0, got 112.
2019-05-09 19:35:26.139609+0200 MonitorControl[19792:1552773] Checksum of reply does not match. Expected 112, got 109.
2019-05-09 19:35:26.154186+0200 MonitorControl[19792:1552779] Checksum of reply does not match. Expected 55, got 113.
2019-05-09 19:35:26.154393+0200 MonitorControl[19792:1552779] Reading 98 failed.
2019-05-09 19:35:26.154859+0200 MonitorControl[19792:1552779] LG ULTRAWIDE (DDC.DDC.Command.audioSpeakerVolume):
2019-05-09 19:35:26.154927+0200 MonitorControl[19792:1552779]  - current value: 0
2019-05-09 19:35:26.154980+0200 MonitorControl[19792:1552779]  - maximum value: 0
2019-05-09 19:35:26.441498+0200 MonitorControl[19792:1552773] Got wrong response type for 16. Expected 2, got 190.
2019-05-09 19:35:26.441581+0200 MonitorControl[19792:1552773] Reading 16 failed.
2019-05-09 19:35:26.441807+0200 MonitorControl[19792:1552773] LG ULTRAWIDE (DDC.DDC.Command.brightness):
2019-05-09 19:35:26.441864+0200 MonitorControl[19792:1552773]  - current value: 0
2019-05-09 19:35:26.441901+0200 MonitorControl[19792:1552773]  - maximum value: 0

Let me know if there's anything else you'd like me to test.

Interesting that you actually get a response and “only” the checksum doesn't match. It clearly seems to be returning “something” as least.

@JoniVR, did anything change with the latest changes to DDC.swift?

Ok, I ran it again, 100 tries, default minReplyDelay, Displayport cable, d803f92
I don't see much difference, ran it 3 times in total to be sure.
Only difference I can make out is it now says Display does not support DDC on some lines
2019-05-10 19:53:43.773254+0200 MonitorControl[7604:342269] kIOI2CSimpleTransactionType is supported.
2019-05-10 19:53:43.917376+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 241, got 191.
2019-05-10 19:53:43.918038+0200 MonitorControl[7604:342321] Display does not support DDC.
2019-05-10 19:53:43.938496+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 86.
2019-05-10 19:53:43.939040+0200 MonitorControl[7604:342309] Display does not support DDC.
2019-05-10 19:53:43.942546+0200 MonitorControl[7604:342321] Display supports DDC (enableAppReport).

Full Log
2019-05-10 19:53:43.707803+0200 MonitorControl[7604:342269] Service port vendor ID 0 differs from display product ID 7789.
2019-05-10 19:53:43.708119+0200 MonitorControl[7604:342269] Service port vendor ID 0 differs from display product ID 7789.
2019-05-10 19:53:43.713522+0200 MonitorControl[7604:342269] Framebuffer: AppleIntelFramebuffer
2019-05-10 19:53:43.713593+0200 MonitorControl[7604:342269] Location: IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/IGPU@2/AppleIntelFramebuffer@1/display0/AppleDisplay
2019-05-10 19:53:43.713615+0200 MonitorControl[7604:342269] Vendor ID: 7789, Product ID: 30436, Serial Number: 451657
2019-05-10 19:53:43.713675+0200 MonitorControl[7604:342269] Unit Number: 1
2019-05-10 19:53:43.713692+0200 MonitorControl[7604:342269] Service Port: 47387
2019-05-10 19:53:43.714458+0200 MonitorControl[7604:342269] kIOI2CSimpleTransactionType is supported.
2019-05-10 19:53:43.714786+0200 MonitorControl[7604:342269] Service port vendor ID 0 differs from display product ID 7789.
2019-05-10 19:53:43.715062+0200 MonitorControl[7604:342269] Service port vendor ID 0 differs from display product ID 7789.
2019-05-10 19:53:43.717690+0200 MonitorControl[7604:342269] Framebuffer: AppleIntelFramebuffer
2019-05-10 19:53:43.721639+0200 MonitorControl[7604:342269] Location: IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/IGPU@2/AppleIntelFramebuffer@1/display0/AppleDisplay
2019-05-10 19:53:43.721675+0200 MonitorControl[7604:342269] Vendor ID: 7789, Product ID: 30436, Serial Number: 451657
2019-05-10 19:53:43.721745+0200 MonitorControl[7604:342269] Unit Number: 1
2019-05-10 19:53:43.721770+0200 MonitorControl[7604:342269] Service Port: 47387
2019-05-10 19:53:43.724700+0200 MonitorControl[7604:342269] The following supported displays were found:
2019-05-10 19:53:43.727899+0200 MonitorControl[7604:342269]  - LG ULTRAWIDE (Vendor: 7789, Model: 30436)
2019-05-10 19:53:43.728289+0200 MonitorControl[7604:342269] Service port vendor ID 0 differs from display product ID 7789.
2019-05-10 19:53:43.728577+0200 MonitorControl[7604:342269] Service port vendor ID 0 differs from display product ID 7789.
2019-05-10 19:53:43.730961+0200 MonitorControl[7604:342269] Framebuffer: AppleIntelFramebuffer
2019-05-10 19:53:43.732132+0200 MonitorControl[7604:342269] Location: IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/IGPU@2/AppleIntelFramebuffer@1/display0/AppleDisplay
2019-05-10 19:53:43.732188+0200 MonitorControl[7604:342269] Vendor ID: 7789, Product ID: 30436, Serial Number: 451657
2019-05-10 19:53:43.732249+0200 MonitorControl[7604:342269] Unit Number: 1
2019-05-10 19:53:43.732271+0200 MonitorControl[7604:342269] Service Port: 47387
2019-05-10 19:53:43.732906+0200 MonitorControl[7604:342269] kIOI2CSimpleTransactionType is supported.
2019-05-10 19:53:43.746760+0200 MonitorControl[7604:342269] Service port vendor ID 0 differs from display product ID 7789.
2019-05-10 19:53:43.747575+0200 MonitorControl[7604:342269] Service port vendor ID 0 differs from display product ID 7789.
2019-05-10 19:53:43.752603+0200 MonitorControl[7604:342269] Framebuffer: AppleIntelFramebuffer
2019-05-10 19:53:43.752828+0200 MonitorControl[7604:342269] Location: IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/IGPU@2/AppleIntelFramebuffer@1/display0/AppleDisplay
2019-05-10 19:53:43.752894+0200 MonitorControl[7604:342269] Vendor ID: 7789, Product ID: 30436, Serial Number: 451657
2019-05-10 19:53:43.752972+0200 MonitorControl[7604:342269] Unit Number: 1
2019-05-10 19:53:43.752994+0200 MonitorControl[7604:342269] Service Port: 47387
2019-05-10 19:53:43.756219+0200 MonitorControl[7604:342269] Service port vendor ID 0 differs from display product ID 7789.
2019-05-10 19:53:43.756545+0200 MonitorControl[7604:342269] Service port vendor ID 0 differs from display product ID 7789.
2019-05-10 19:53:43.759080+0200 MonitorControl[7604:342269] Framebuffer: AppleIntelFramebuffer
2019-05-10 19:53:43.759119+0200 MonitorControl[7604:342269] Location: IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/IGPU@2/AppleIntelFramebuffer@1/display0/AppleDisplay
2019-05-10 19:53:43.772388+0200 MonitorControl[7604:342269] Vendor ID: 7789, Product ID: 30436, Serial Number: 451657
2019-05-10 19:53:43.772564+0200 MonitorControl[7604:342269] Unit Number: 1
2019-05-10 19:53:43.772589+0200 MonitorControl[7604:342269] Service Port: 47387
2019-05-10 19:53:43.773254+0200 MonitorControl[7604:342269] kIOI2CSimpleTransactionType is supported.
2019-05-10 19:53:43.917376+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 241, got 191.
2019-05-10 19:53:43.918038+0200 MonitorControl[7604:342321] Display does not support DDC.
2019-05-10 19:53:43.938496+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 86.
2019-05-10 19:53:43.939040+0200 MonitorControl[7604:342309] Display does not support DDC.
2019-05-10 19:53:43.942546+0200 MonitorControl[7604:342321] Display supports DDC (enableAppReport).
2019-05-10 19:53:44.065006+0200 MonitorControl[7604:342321] Failed to send request to interface 0 for framebuffer with ID 47387.
2019-05-10 19:53:44.068184+0200 MonitorControl[7604:342309] Display supports DDC (enableAppReport).
2019-05-10 19:53:44.194843+0200 MonitorControl[7604:342321] Failed to send request to interface 0 for framebuffer with ID 47387.
2019-05-10 19:53:44.214841+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 191.
2019-05-10 19:53:44.387346+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 32, got 86.
2019-05-10 19:53:44.414833+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 224, got 202.
2019-05-10 19:53:44.514875+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 32, got 9.
2019-05-10 19:53:44.530007+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 82.
2019-05-10 19:53:44.730853+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 3, got 94.
2019-05-10 19:53:44.746377+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 15, got 80.
2019-05-10 19:53:44.940083+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 2, got 98.
2019-05-10 19:53:44.964872+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 109.
2019-05-10 19:53:45.232183+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 1.
2019-05-10 19:53:45.264917+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 84.
2019-05-10 19:53:45.425966+0200 MonitorControl[7604:342309] Failed to send request to interface 0 for framebuffer with ID 47387.
2019-05-10 19:53:45.441127+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 62.
2019-05-10 19:53:45.631091+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 30.
2019-05-10 19:53:45.647338+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 32, got 75.
2019-05-10 19:53:45.929781+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 71.
2019-05-10 19:53:45.944909+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 46, got 56.
2019-05-10 19:53:46.230510+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 103.
2019-05-10 19:53:46.246012+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 83.
2019-05-10 19:53:46.431274+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 81.
2019-05-10 19:53:46.446437+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 3, got 94.
2019-05-10 19:53:46.730055+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 92.
2019-05-10 19:53:46.745190+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 112.
2019-05-10 19:53:47.031081+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 112, got 109.
2019-05-10 19:53:47.047104+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 55, got 113.
2019-05-10 19:53:47.331113+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 32, got 38.
2019-05-10 19:53:47.346381+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 56, got 66.
2019-05-10 19:53:47.631133+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 121.
2019-05-10 19:53:47.646462+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 3, got 113.
2019-05-10 19:53:47.930378+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 95.
2019-05-10 19:53:47.945579+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 80.
2019-05-10 19:53:48.230952+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 48, got 95.
2019-05-10 19:53:48.245914+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 53, got 90.
2019-05-10 19:53:48.515224+0200 MonitorControl[7604:342309] Failed to send request to interface 0 for framebuffer with ID 47387.
2019-05-10 19:53:48.530780+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 14.
2019-05-10 19:53:48.830165+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 108.
2019-05-10 19:53:48.844835+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 9.
2019-05-10 19:53:49.129873+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 64, got 94.
2019-05-10 19:53:49.146693+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 101.
2019-05-10 19:53:49.430064+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 2, got 73.
2019-05-10 19:53:49.446000+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 58.
2019-05-10 19:53:49.629942+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 55, got 126.
2019-05-10 19:53:49.645518+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 115.
2019-05-10 19:53:49.829706+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 114.
2019-05-10 19:53:49.845899+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 94.
2019-05-10 19:53:50.031905+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 83.
2019-05-10 19:53:50.065107+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 125.
2019-05-10 19:53:50.315233+0200 MonitorControl[7604:342309] Failed to send request to interface 0 for framebuffer with ID 47387.
2019-05-10 19:53:50.330876+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 111.
2019-05-10 19:53:50.615215+0200 MonitorControl[7604:342309] Failed to send request to interface 0 for framebuffer with ID 47387.
2019-05-10 19:53:50.629892+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 1.
2019-05-10 19:53:50.929787+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 32, got 49.
2019-05-10 19:53:50.945376+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 32, got 80.
2019-05-10 19:53:51.230100+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 224, got 80.
2019-05-10 19:53:51.246110+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 144.
2019-05-10 19:53:51.529779+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 28, got 66.
2019-05-10 19:53:51.545959+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 81.
2019-05-10 19:53:51.729979+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 94.
2019-05-10 19:53:51.744867+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 15, got 101.
2019-05-10 19:53:51.929878+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 46, got 21.
2019-05-10 19:53:51.945732+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 104.
2019-05-10 19:53:52.231163+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 35.
2019-05-10 19:53:52.246215+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 112.
2019-05-10 19:53:52.480881+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 38.
2019-05-10 19:53:52.495889+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 125.
2019-05-10 19:53:52.681167+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 7.
2019-05-10 19:53:52.697676+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 118.
2019-05-10 19:53:52.966672+0200 MonitorControl[7604:342309] Failed to send request to interface 0 for framebuffer with ID 47387.
2019-05-10 19:53:52.982993+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 3, got 71.
2019-05-10 19:53:53.266507+0200 MonitorControl[7604:342309] Failed to send request to interface 0 for framebuffer with ID 47387.
2019-05-10 19:53:53.281238+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 113.
2019-05-10 19:53:53.482760+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 92.
2019-05-10 19:53:53.497826+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 80.
2019-05-10 19:53:53.781183+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 79.
2019-05-10 19:53:53.796282+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 106.
2019-05-10 19:53:53.981117+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 59.
2019-05-10 19:53:53.996104+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 4, got 58.
2019-05-10 19:53:54.245050+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 32, got 80.
2019-05-10 19:53:54.266400+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 28, got 36.
2019-05-10 19:53:54.495396+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 59.
2019-05-10 19:53:54.516400+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 81.
2019-05-10 19:53:54.746378+0200 MonitorControl[7604:342321] Failed to send request to interface 0 for framebuffer with ID 47387.
2019-05-10 19:53:54.766417+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 3, got 94.
2019-05-10 19:53:55.031170+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 92.
2019-05-10 19:53:55.045649+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 96.
2019-05-10 19:53:55.230033+0200 MonitorControl[7604:342309] Failed to send request to interface 0 for framebuffer with ID 47387.
2019-05-10 19:53:55.244880+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 112, got 109.
2019-05-10 19:53:55.430047+0200 MonitorControl[7604:342321] Failed to send request to interface 0 for framebuffer with ID 47387.
2019-05-10 19:53:55.444619+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 55, got 113.
2019-05-10 19:53:55.731302+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 99.
2019-05-10 19:53:55.747274+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 30.
2019-05-10 19:53:55.916615+0200 MonitorControl[7604:342321] Failed to send request to interface 0 for framebuffer with ID 47387.
2019-05-10 19:53:55.931889+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 11.
2019-05-10 19:53:56.147352+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 32, got 94.
2019-05-10 19:53:56.167751+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 103.
2019-05-10 19:53:56.483129+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 16, got 22.
2019-05-10 19:53:56.517704+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 32, got 119.
2019-05-10 19:53:56.767899+0200 MonitorControl[7604:342309] Failed to send request to interface 0 for framebuffer with ID 47387.
2019-05-10 19:53:56.783674+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 3, got 115.
2019-05-10 19:53:57.067898+0200 MonitorControl[7604:342309] Failed to send request to interface 0 for framebuffer with ID 47387.
2019-05-10 19:53:57.083304+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 66.
2019-05-10 19:53:57.283462+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 77.
2019-05-10 19:53:57.317698+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 94.
2019-05-10 19:53:57.397921+0200 MonitorControl[7604:342309] Failed to send request to interface 0 for framebuffer with ID 47387.
2019-05-10 19:53:57.417797+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 117.
2019-05-10 19:53:57.683252+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 26.
2019-05-10 19:53:57.697913+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 128, got 40.
2019-05-10 19:53:57.967952+0200 MonitorControl[7604:342321] Failed to send request to interface 0 for framebuffer with ID 47387.
2019-05-10 19:53:57.983528+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 32, got 200.
2019-05-10 19:53:58.244643+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 224, got 10.
2019-05-10 19:53:58.267754+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 233.
2019-05-10 19:53:58.482990+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 114.
2019-05-10 19:53:58.498877+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 94.
2019-05-10 19:53:58.683515+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 83.
2019-05-10 19:53:58.717789+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 109.
2019-05-10 19:53:58.967963+0200 MonitorControl[7604:342309] Failed to send request to interface 0 for framebuffer with ID 47387.
2019-05-10 19:53:58.983737+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 111.
2019-05-10 19:53:59.269207+0200 MonitorControl[7604:342321] Failed to send request to interface 0 for framebuffer with ID 47387.
2019-05-10 19:53:59.284027+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 1.
2019-05-10 19:53:59.569849+0200 MonitorControl[7604:342309] Failed to send request to interface 0 for framebuffer with ID 47387.
2019-05-10 19:53:59.584239+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 55, got 99.
2019-05-10 19:53:59.885150+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 62.
2019-05-10 19:53:59.919021+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 30.
2019-05-10 19:54:00.183760+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 75.
2019-05-10 19:54:00.219075+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 2, got 101.
2019-05-10 19:54:00.369184+0200 MonitorControl[7604:342321] Failed to send request to interface 0 for framebuffer with ID 47387.
2019-05-10 19:54:00.384740+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 56.
2019-05-10 19:54:00.484079+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 73.
2019-05-10 19:54:00.519070+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 83.
2019-05-10 19:54:00.669200+0200 MonitorControl[7604:342309] Failed to send request to interface 0 for framebuffer with ID 47387.
2019-05-10 19:54:00.683661+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 3, got 82.
2019-05-10 19:54:00.969200+0200 MonitorControl[7604:342321] Failed to send request to interface 0 for framebuffer with ID 47387.
2019-05-10 19:54:00.984934+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 94.
2019-05-10 19:54:01.284437+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 95.
2019-05-10 19:54:01.319152+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 112.
2019-05-10 19:54:01.584954+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 109.
2019-05-10 19:54:01.619068+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 1.
2019-05-10 19:54:01.734953+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 32, got 49.
2019-05-10 19:54:01.769089+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 28, got 126.
2019-05-10 19:54:02.034989+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 3, got 66.
2019-05-10 19:54:02.069096+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 113.
2019-05-10 19:54:02.234142+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 92.
2019-05-10 19:54:02.269137+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 80.
2019-05-10 19:54:02.441379+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 95.
2019-05-10 19:54:02.469595+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 106.
2019-05-10 19:54:02.735073+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 59.
2019-05-10 19:54:02.769100+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 108.
2019-05-10 19:54:02.985008+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 46, got 39.
2019-05-10 19:54:03.019128+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 94.
2019-05-10 19:54:03.284795+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 37.
2019-05-10 19:54:03.320403+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 73.
2019-05-10 19:54:03.520546+0200 MonitorControl[7604:342309] Failed to send request to interface 0 for framebuffer with ID 47387.
2019-05-10 19:54:03.536243+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 8, got 48.
2019-05-10 19:54:03.735589+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 126.
2019-05-10 19:54:03.770496+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 68.
2019-05-10 19:54:04.020627+0200 MonitorControl[7604:342309] Failed to send request to interface 0 for framebuffer with ID 47387.
2019-05-10 19:54:04.035523+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 114.
2019-05-10 19:54:04.336184+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 1, got 95.
2019-05-10 19:54:04.370382+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 2, got 81.
2019-05-10 19:54:04.636558+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 125.
2019-05-10 19:54:04.670448+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 111.
2019-05-10 19:54:04.936490+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 15, got 14.
2019-05-10 19:54:04.970400+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 49.
2019-05-10 19:54:05.135493+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 32, got 80.
2019-05-10 19:54:05.170858+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 112, got 0.
2019-05-10 19:54:05.471672+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 3, got 115.
2019-05-10 19:54:05.487774+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 66.
2019-05-10 19:54:05.771907+0200 MonitorControl[7604:342309] Failed to send request to interface 0 for framebuffer with ID 47387.
2019-05-10 19:54:05.786622+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 77.
2019-05-10 19:54:06.086479+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 94.
2019-05-10 19:54:06.121693+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 101.
2019-05-10 19:54:06.386749+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 26.
2019-05-10 19:54:06.421694+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 70.
2019-05-10 19:54:06.671942+0200 MonitorControl[7604:342321] Failed to send request to interface 0 for framebuffer with ID 47387.
2019-05-10 19:54:06.687695+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 64, got 99.
2019-05-10 19:54:06.986581+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 46, got 94.
2019-05-10 19:54:07.021718+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 3, got 37.
2019-05-10 19:54:07.271967+0200 MonitorControl[7604:342321] Failed to send request to interface 0 for framebuffer with ID 47387.
2019-05-10 19:54:07.286678+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 125.
2019-05-10 19:54:07.572415+0200 MonitorControl[7604:342309] Failed to send request to interface 0 for framebuffer with ID 47387.
2019-05-10 19:54:07.587277+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 7.
2019-05-10 19:54:07.871888+0200 MonitorControl[7604:342309] Failed to send request to interface 0 for framebuffer with ID 47387.
2019-05-10 19:54:07.887545+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 16, got 102.
2019-05-10 19:54:08.190528+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 71.
2019-05-10 19:54:08.221734+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 2, got 112.
2019-05-10 19:54:08.471937+0200 MonitorControl[7604:342321] Failed to send request to interface 0 for framebuffer with ID 47387.
2019-05-10 19:54:08.487396+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 92.
2019-05-10 19:54:08.771942+0200 MonitorControl[7604:342321] Failed to send request to interface 0 for framebuffer with ID 47387.
2019-05-10 19:54:08.786664+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 1, got 81.
2019-05-10 19:54:09.086727+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 16, got 95.
2019-05-10 19:54:09.121822+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 106.
2019-05-10 19:54:09.337681+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 0, got 59.
2019-05-10 19:54:09.371832+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 2, got 56.
2019-05-10 19:54:09.638390+0200 MonitorControl[7604:342321] Checksum of reply does not match. Expected 32, got 116.
2019-05-10 19:54:09.673026+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 14, got 10.
2019-05-10 19:54:09.823513+0200 MonitorControl[7604:342321] Failed to send request to interface 0 for framebuffer with ID 47387.
2019-05-10 19:54:09.824088+0200 MonitorControl[7604:342321] Reading 98 failed.
2019-05-10 19:54:09.826739+0200 MonitorControl[7604:342321] LG ULTRAWIDE (DDC.DDC.Command.audioSpeakerVolume):
2019-05-10 19:54:09.826870+0200 MonitorControl[7604:342321]  - current value: 0
2019-05-10 19:54:09.826904+0200 MonitorControl[7604:342321]  - maximum value: 0
2019-05-10 19:54:09.839587+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 0, got 39.
2019-05-10 19:54:10.138004+0200 MonitorControl[7604:342309] Checksum of reply does not match. Expected 3, got 82.
2019-05-10 19:54:10.138151+0200 MonitorControl[7604:342309] Reading 16 failed.
2019-05-10 19:54:10.138840+0200 MonitorControl[7604:342309] LG ULTRAWIDE (DDC.DDC.Command.luminance):
2019-05-10 19:54:10.138885+0200 MonitorControl[7604:342309]  - current value: 0
2019-05-10 19:54:10.138905+0200 MonitorControl[7604:342309]  - maximum value: 0

I added some more logging when the checksum fails.

Same as before, on c8ed85f

Log
2019-05-15 19:51:13.097597+0200 MonitorControl[73359:7163842] Service port vendor ID 0 differs from display product ID 7789.
2019-05-15 19:51:13.097973+0200 MonitorControl[73359:7163842] Service port vendor ID 0 differs from display product ID 7789.
2019-05-15 19:51:13.103347+0200 MonitorControl[73359:7163842] Framebuffer: AppleIntelFramebuffer
2019-05-15 19:51:13.103474+0200 MonitorControl[73359:7163842] Location: IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/IGPU@2/AppleIntelFramebuffer@1/display0/AppleDisplay
2019-05-15 19:51:13.103504+0200 MonitorControl[73359:7163842] Vendor ID: 7789, Product ID: 30436, Serial Number: 451657
2019-05-15 19:51:13.103656+0200 MonitorControl[73359:7163842] Unit Number: 1
2019-05-15 19:51:13.103687+0200 MonitorControl[73359:7163842] Service Port: 49947
2019-05-15 19:51:13.104611+0200 MonitorControl[73359:7163842] kIOI2CSimpleTransactionType is supported.
2019-05-15 19:51:13.104986+0200 MonitorControl[73359:7163842] Service port vendor ID 0 differs from display product ID 7789.
2019-05-15 19:51:13.105323+0200 MonitorControl[73359:7163842] Service port vendor ID 0 differs from display product ID 7789.
2019-05-15 19:51:13.108187+0200 MonitorControl[73359:7163842] Framebuffer: AppleIntelFramebuffer
2019-05-15 19:51:13.108235+0200 MonitorControl[73359:7163842] Location: IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/IGPU@2/AppleIntelFramebuffer@1/display0/AppleDisplay
2019-05-15 19:51:13.108884+0200 MonitorControl[73359:7163842] Vendor ID: 7789, Product ID: 30436, Serial Number: 451657
2019-05-15 19:51:13.108964+0200 MonitorControl[73359:7163842] Unit Number: 1
2019-05-15 19:51:13.108986+0200 MonitorControl[73359:7163842] Service Port: 49947
2019-05-15 19:51:13.111844+0200 MonitorControl[73359:7163842] The following supported displays were found:
2019-05-15 19:51:13.115979+0200 MonitorControl[73359:7163842]  - LG ULTRAWIDE (Vendor: 7789, Model: 30436)
2019-05-15 19:51:13.116428+0200 MonitorControl[73359:7163842] Service port vendor ID 0 differs from display product ID 7789.
2019-05-15 19:51:13.116756+0200 MonitorControl[73359:7163842] Service port vendor ID 0 differs from display product ID 7789.
2019-05-15 19:51:13.119195+0200 MonitorControl[73359:7163842] Framebuffer: AppleIntelFramebuffer
2019-05-15 19:51:13.119244+0200 MonitorControl[73359:7163842] Location: IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/IGPU@2/AppleIntelFramebuffer@1/display0/AppleDisplay
2019-05-15 19:51:13.119265+0200 MonitorControl[73359:7163842] Vendor ID: 7789, Product ID: 30436, Serial Number: 451657
2019-05-15 19:51:13.119323+0200 MonitorControl[73359:7163842] Unit Number: 1
2019-05-15 19:51:13.119343+0200 MonitorControl[73359:7163842] Service Port: 49947
2019-05-15 19:51:13.119989+0200 MonitorControl[73359:7163842] kIOI2CSimpleTransactionType is supported.
2019-05-15 19:51:13.120353+0200 MonitorControl[73359:7163842] Service port vendor ID 0 differs from display product ID 7789.
2019-05-15 19:51:13.120696+0200 MonitorControl[73359:7163842] Service port vendor ID 0 differs from display product ID 7789.
2019-05-15 19:51:13.123183+0200 MonitorControl[73359:7163842] Framebuffer: AppleIntelFramebuffer
2019-05-15 19:51:13.123232+0200 MonitorControl[73359:7163842] Location: IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/IGPU@2/AppleIntelFramebuffer@1/display0/AppleDisplay
2019-05-15 19:51:13.123253+0200 MonitorControl[73359:7163842] Vendor ID: 7789, Product ID: 30436, Serial Number: 451657
2019-05-15 19:51:13.123307+0200 MonitorControl[73359:7163842] Unit Number: 1
2019-05-15 19:51:13.123325+0200 MonitorControl[73359:7163842] Service Port: 49947
2019-05-15 19:51:13.126270+0200 MonitorControl[73359:7163842] Service port vendor ID 0 differs from display product ID 7789.
2019-05-15 19:51:13.126591+0200 MonitorControl[73359:7163842] Service port vendor ID 0 differs from display product ID 7789.
2019-05-15 19:51:13.129097+0200 MonitorControl[73359:7163842] Framebuffer: AppleIntelFramebuffer
2019-05-15 19:51:13.129143+0200 MonitorControl[73359:7163842] Location: IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/IGPU@2/AppleIntelFramebuffer@1/display0/AppleDisplay
2019-05-15 19:51:13.129164+0200 MonitorControl[73359:7163842] Vendor ID: 7789, Product ID: 30436, Serial Number: 451657
2019-05-15 19:51:13.129246+0200 MonitorControl[73359:7163842] Unit Number: 1
2019-05-15 19:51:13.129269+0200 MonitorControl[73359:7163842] Service Port: 49947
2019-05-15 19:51:13.129892+0200 MonitorControl[73359:7163842] kIOI2CSimpleTransactionType is supported.
2019-05-15 19:51:13.247983+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 103.
2019-05-15 19:51:13.248597+0200 MonitorControl[73359:7164017] Display does not support DDC.
2019-05-15 19:51:13.405774+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:13.406828+0200 MonitorControl[73359:7164017] Display does not support enabling DDC application report.
2019-05-15 19:51:13.421608+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 4, got 80.
2019-05-15 19:51:13.421662+0200 MonitorControl[73359:7164018] Display does not support DDC.
2019-05-15 19:51:13.713352+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:13.722452+0200 MonitorControl[73359:7164018] Display supports enabling DDC application report.
2019-05-15 19:51:14.009650+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:14.024654+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 158, got 59.
2019-05-15 19:51:14.207950+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:14.246719+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 56, got 66.
2019-05-15 19:51:14.406158+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:14.421408+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 0, got 121.
2019-05-15 19:51:14.695670+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:14.710675+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 3, got 113.
2019-05-15 19:51:15.022974+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:15.045219+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 95.
2019-05-15 19:51:15.295436+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:15.310302+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 80.
2019-05-15 19:51:15.595438+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:15.610419+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 48, got 95.
2019-05-15 19:51:15.712423+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:15.726208+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 53, got 90.
2019-05-15 19:51:15.895577+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:15.909774+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 0, got 14.
2019-05-15 19:51:16.095495+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:16.110195+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 0, got 108.
2019-05-15 19:51:16.395471+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:16.410645+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 9.
2019-05-15 19:51:16.695601+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:16.709801+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 64, got 94.
2019-05-15 19:51:16.895560+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:16.910603+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 101.
2019-05-15 19:51:17.195477+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:17.210515+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 2, got 73.
2019-05-15 19:51:17.495654+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:17.510284+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 58.
2019-05-15 19:51:17.695585+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:17.710239+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 55, got 126.
2019-05-15 19:51:17.995535+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:18.010392+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 0, got 115.
2019-05-15 19:51:18.246139+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:18.261124+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 0, got 114.
2019-05-15 19:51:18.545446+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:18.560390+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 94.
2019-05-15 19:51:18.845452+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:18.860858+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 83.
2019-05-15 19:51:19.145684+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:19.160986+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 0, got 125.
2019-05-15 19:51:19.453108+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:19.476972+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 111.
2019-05-15 19:51:19.746017+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:19.761651+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 1.
2019-05-15 19:51:20.045629+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:20.060378+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 32, got 49.
2019-05-15 19:51:20.345708+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:20.360659+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 32, got 80.
2019-05-15 19:51:20.645757+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:20.660735+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 224, got 80.
2019-05-15 19:51:20.945680+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:20.960615+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 144.
2019-05-15 19:51:21.195653+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:21.210487+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 28, got 66.
2019-05-15 19:51:21.495725+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:21.511069+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 81.
2019-05-15 19:51:21.798701+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:21.813035+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 94.
2019-05-15 19:51:22.095586+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:22.110124+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 15, got 101.
2019-05-15 19:51:22.395592+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:22.410069+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 46, got 21.
2019-05-15 19:51:22.595540+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:22.610853+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 104.
2019-05-15 19:51:22.795606+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:22.810394+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 0, got 35.
2019-05-15 19:51:23.095590+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:23.111480+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 0, got 112.
2019-05-15 19:51:23.395758+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:23.410434+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 38.
2019-05-15 19:51:23.595645+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:23.610315+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 125.
2019-05-15 19:51:23.800891+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:23.815636+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 7.
2019-05-15 19:51:24.095670+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:24.109952+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 118.
2019-05-15 19:51:24.395891+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:24.410860+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 3, got 71.
2019-05-15 19:51:24.696031+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:24.710482+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 113.
2019-05-15 19:51:24.995739+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:25.013181+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 92.
2019-05-15 19:51:25.195862+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:25.210592+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 80.
2019-05-15 19:51:25.495836+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:25.510039+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 79.
2019-05-15 19:51:25.702193+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:25.716343+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 0, got 106.
2019-05-15 19:51:25.995778+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:26.011224+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 0, got 59.
2019-05-15 19:51:26.197784+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:26.212582+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 4, got 58.
2019-05-15 19:51:26.395722+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:26.410944+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 32, got 80.
2019-05-15 19:51:26.695798+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:26.710910+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 28, got 36.
2019-05-15 19:51:26.996997+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:27.011736+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 59.
2019-05-15 19:51:27.196902+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:27.211569+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 0, got 81.
2019-05-15 19:51:27.396979+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:27.412431+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 3, got 94.
2019-05-15 19:51:27.661590+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:27.676889+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 92.
2019-05-15 19:51:27.947634+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:27.962138+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 96.
2019-05-15 19:51:28.160783+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:28.176606+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 112, got 109.
2019-05-15 19:51:28.447023+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:28.461833+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 55, got 113.
2019-05-15 19:51:28.747018+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:28.762114+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 0, got 99.
2019-05-15 19:51:28.951536+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:28.967593+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 30.
2019-05-15 19:51:29.247287+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:29.262571+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 11.
2019-05-15 19:51:29.547241+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:29.562707+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 32, got 94.
2019-05-15 19:51:29.847035+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:29.862816+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 0, got 103.
2019-05-15 19:51:30.147255+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:30.162152+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 16, got 22.
2019-05-15 19:51:30.448324+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:30.463268+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 32, got 119.
2019-05-15 19:51:30.697590+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:30.712686+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 3, got 115.
2019-05-15 19:51:30.901845+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:30.916866+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 0, got 66.
2019-05-15 19:51:31.197272+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:31.214224+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 77.
2019-05-15 19:51:31.501599+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:31.520321+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 0, got 94.
2019-05-15 19:51:31.797174+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:31.811174+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 117.
2019-05-15 19:51:32.097281+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:32.120046+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 0, got 26.
2019-05-15 19:51:32.397407+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:32.412608+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 128, got 40.
2019-05-15 19:51:32.699843+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:32.715107+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 32, got 200.
2019-05-15 19:51:32.947300+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:32.963015+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 224, got 10.
2019-05-15 19:51:33.248720+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:33.263926+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 233.
2019-05-15 19:51:33.497344+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:33.512827+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 0, got 114.
2019-05-15 19:51:33.797170+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:33.812826+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 0, got 94.
2019-05-15 19:51:34.097422+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:34.112207+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 83.
2019-05-15 19:51:34.397440+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:34.412158+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 109.
2019-05-15 19:51:34.697439+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:34.712699+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 0, got 111.
2019-05-15 19:51:34.997315+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:35.012619+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 0, got 1.
2019-05-15 19:51:35.297171+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:35.313887+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 55, got 99.
2019-05-15 19:51:35.598179+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:35.617797+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 62.
2019-05-15 19:51:35.797121+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:35.814923+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 0, got 30.
2019-05-15 19:51:36.097456+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:36.113421+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 0, got 75.
2019-05-15 19:51:36.397602+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:36.414559+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 2, got 101.
2019-05-15 19:51:36.708594+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:36.723190+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 56.
2019-05-15 19:51:36.997323+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:37.012448+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 0, got 73.
2019-05-15 19:51:37.297745+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:37.314222+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 83.
2019-05-15 19:51:37.597367+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:37.614390+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 3, got 82.
2019-05-15 19:51:37.897498+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:37.912957+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 0, got 94.
2019-05-15 19:51:38.177186+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:38.197258+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 0, got 95.
2019-05-15 19:51:38.448345+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:38.463597+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 112.
2019-05-15 19:51:38.751465+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:38.765324+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 0, got 109.
2019-05-15 19:51:39.049398+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:39.064241+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 0, got 1.
2019-05-15 19:51:39.350345+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:39.365557+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 32, got 49.
2019-05-15 19:51:39.653752+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:39.666912+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 28, got 126.
2019-05-15 19:51:39.947378+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:39.962936+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 3, got 66.
2019-05-15 19:51:40.247577+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:40.263319+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 113.
2019-05-15 19:51:40.547466+0200 MonitorControl[73359:7164018] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:40.563312+0200 MonitorControl[73359:7164017] Checksum of reply does not match. Expected 0, got 92.
2019-05-15 19:51:40.762862+0200 MonitorControl[73359:7164017] Failed to send request to interface 0 for framebuffer with ID 49947.
2019-05-15 19:51:40.768235+0200 MonitorControl[73359:7164017] Reading 98 failed.
2019-05-15 19:51:40.768964+0200 MonitorControl[73359:7164017] LG ULTRAWIDE (DDC.DDC.Command.audioSpeakerVolume):
2019-05-15 19:51:40.769024+0200 MonitorControl[73359:7164017]  - current value: 0
2019-05-15 19:51:40.769047+0200 MonitorControl[73359:7164017]  - maximum value: 0
2019-05-15 19:51:40.779369+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 0, got 80.
2019-05-15 19:51:41.063377+0200 MonitorControl[73359:7164018] Checksum of reply does not match. Expected 0, got 95.
2019-05-15 19:51:41.063453+0200 MonitorControl[73359:7164018] Reading 16 failed.
2019-05-15 19:51:41.063708+0200 MonitorControl[73359:7164018] LG ULTRAWIDE (DDC.DDC.Command.luminance):
2019-05-15 19:51:41.063747+0200 MonitorControl[73359:7164018]  - current value: 0
2019-05-15 19:51:41.063771+0200 MonitorControl[73359:7164018]  - maximum value: 0

check near the bottom

The values at the bottom are the last saved values, so no change here.
You'll have to try messing around with the DDC.swift repo yourself, see if you stumble upon anything useful.

The values at the bottom are the last saved values, so no change here, both reads are still failing.

I know that, I usually uncomment that part and replace it with (0,0) to make debugging easier. I meant the bottom of the log ;)
2019-05-16 21:49:14.911864+0200 MonitorControl[25653:8952899] Checksum of reply does not match. Expected 0, got 99.
2019-05-16 21:49:14.912077+0200 MonitorControl[25653:8952899] Response was: 00 00 04 00 00 00 37 00 00 00 00
2019-05-16 21:49:15.130448+0200 MonitorControl[25653:8952899] Checksum of reply does not match. Expected 0, got 30.
2019-05-16 21:49:15.130567+0200 MonitorControl[25653:8952899] Response was: 40 00 00 2E 00 00 00 00 20 00 00

I'll playing around with it in somewhere the future to see if there's anything I can find. Thanks for the effort on this.

Yeah, these responses seem pretty random, the only one which comes “close” to a valid response is the first one where we are sending F1 and it should return 6E 80 BE, but it returns 6E 81 F1.

Actually this first one succeeded one time in the first log:
2019-05-15 19:51:13.722452+0200 MonitorControl[73359:7164018] Display supports enabling DDC application report.

GPU
Display
Connection
minReplyDelay

Intel HD 460
Acer Predator XB271HU
USB-C -> HDMI
no brightness or sound

I'm not sure if this project is limited to LG displays or not but this was my testing with my Acer Predator :(

High Sierra 10.13.6
Mac Pro 4,1 -> 5,1
Radeon HD 5870 1GB
Fujitsu P24W-3 (straight DVI-D)
Brightness & Volume work perfectly out of the box!
Iiyama XB2283HSU, identified as "PLX2283H-DP" (Mini-DP to DVI-D)
Brightness & Volume work perfectly out of the box!
I'll be shortly upgrading graphic card and monitors and will report back with new combinations.

Latest stable Mojave on MBP 15 2018 (Radeon 555X)
Iiyama PL2779QQ - can't change brigthness and volume (no device detected).

High Sierra 10.13.6
Mac Pro 4,1 -> 5,1
Radeon HD 5870 1GB
Dell P2014H (Mini-DP to DVI-D)
Brightness & Volume work perfectly out of the box!

I can also say I'm having a freezing issue similar to post #193 on a 650M (Macbook Pro Retina 15" Late 2012) and a Dell U2412M. When I unplug my Dell monitor, I can use my laptop again. My Thunderbolt Display works fine though.

This is not necessarily an issue with the app, but most likely affects these test results; if I connect a display panel to my Mac through multiple routes (e.g. DP and HDMI on eGPU + DP on another eGPU + built in USB-C/DP or HDMI depending on model) usually one of the connections become non-functional if FreeSync version is changed or turned on/off on the display. Issue doesn't persist through a reboot.
I only have AMD and the built in Intel GPUs but I think it could happen to Nvidia chips as well because sometimes it's the built-in (Intel UHD) graphics that gets disabled.
@SongHoang I might be able to test this out, I have an rMBP with the piece of * 650M chip,  you mean the mid-2012 iteration right? (There was no late 2012 15" laptop, iirc)

This is not necessarily an issue with the app, but most likely affects these test results; if I connect a display panel to my Mac through multiple routes (e.g. DP and HDMI on eGPU + DP on another eGPU + built in USB-C/DP or HDMI depending on model) usually one of the connections become non-functional if FreeSync version is changed or turned on/off on the display. Issue doesn't persist through a reboot.
I only have AMD and the built in Intel GPUs but I think it could happen to Nvidia chips as well because sometimes it's the built-in (Intel UHD) graphics that gets disabled.
@SongHoang I might be able to test this out, I have an rMBP with the piece of * 650M chip, you mean the mid-2012 iteration right? (There was no late 2012 15" laptop, iirc)

My apologies, its a Mid-2012 15" Macbook Pro Retina.
After a bit of playing around, 1.4.0 works per recommendation from other posts, but has a few issues. If I have all the devices already plugged in (Thunderbolt + Dell U2412M to both Thunderbolt inputs on Macbook) and launch the application, it'll work fine and I can adjust the brightness. But if I have it already running, and plug in the Dell monitor, it'll freeze just like on v2.0.0. No cases will get v2.0.0 working on my end.
Let me know if I can try any another test cases on my end.

Worked right the first time, and with a twist:

Custom built macOS (10.13.6) tower (Intel CPU, not using the onboard graphics)

GPU
Display
Connection
minReplyDelay

EVGA GTX1070
Dell S2716DG
DisplayPort
Default

Thank you
The brightness controls on the monitor are annoying, and now I'm freee!

I had set the display's "Input Select" value to DVI instead of the default "Auto" for it to work.
OSD -> Extra -> Input Select -> DVI. When on auto it would not work. Changing to DVI fixed the issue on the other monitor.
2 AOC 21.5'' AOC Monitors

USB-C -> DVI
USB-C -> DVI
I can't get the model number of the monitors easily without taking them off the mount (its covering the model number) but MacOS identifies them each as 2269W

Mac Mini (2018)
MacOS 10.5.5
Hope this helps for someone else. Great App 👍

Works great for me, including volume (which MacOS couldn't manage before).

GPU
Display
Connection
minReplyDelay
Mac
OS

Radeon Pro 455
Iiyama PL82888UH
DisplayPort
default
MBP 2016
mojave

GPU
Display
Connection
minReplyDelay
Mac
OS

Intel Iris 1536 MB graphics
DELL S2817Q
DisplayPort
default
MacBook Pro (Retina, 13-inch, Mid 2014)
Mojave 10.14.1 (18B75)

Brightness works fine, but I haven't been able to get the sound to work.
I have a dual monitor set up. I've tried either monitor and the Multi-Output(using speakers from both monitors) that I've set up and the audio won't respond to anything. The popup on the screen looks as though the buttons are working, but the sound doesn't adjust. I also tried the ddcctl suggestion. It runs but the screen icon volume level is also not affected by running ./ddcctl -d 1 -v 30 or ./ddcctl -d 1 -v 1. I have tried running in single monitor mode and have had the same results.
I'm not sure what to try from here. Any suggestions?
~/w/p/ddcctl (master) $ ./ddcctl -d 1 -v 1
D: NSScreen #722472906 (2560x1440 0°) HiDPI
D: NSScreen #722472137 (2560x1440 0°) HiDPI
I: found 2 external displays
I: polling display 1's EDID
I: got edid.serial: MTKT1798934I
I: got edid.name: DELL S2817Q
D: action: v: 1
D: setting VCP control #98 => 1

~/w/p/ddcctl (master) $ ./ddcctl -d 1 -v 30
D: NSScreen #722472906 (2560x1440 0°) HiDPI
D: NSScreen #722472137 (2560x1440 0°) HiDPI
I: found 2 external displays
I: polling display 1's EDID
I: got edid.serial: MTKT1798934I
I: got edid.name: DELL S2817Q
D: action: v: 30
D: setting VCP control #98 => 30

GPU
Display
Connection
minReplyDelay
Mac
OS

AMD Radeon RX 580 8 GB
Philips 499p9
DisplayPort
default
MacBook Pro (13-inch, 2019)
Catalina 10.15.7 (19H2)

brightness doesn't work, volume does

GPU
Display
Connection
minReplyDelay

MSI RX 570 Gaming 8GB
LG 27UK650-W
DisplayPort
default

Brightness and volume work out of the box. This is a hackintosh'd Dell PowerEdge T30 using iMac17,1 SMBIOS and running 10.15.7.

GPU
Display
Connection
minReplyRedlay
Mac
OS
MonitorControl

EVGA GeForce GTX 760
Iiyama XUB2792QSU
DisplayPort
default
Hackintosh
10.12
v2.1.0

Writing works out of the box, thanks a lot ! (shows as PL2792Q)
Volume was instant, for brightness to work I had to reboot with the screen connected (probably nvram related).
Read doesn't seem to work at all.
And for easy copy/paste :
| **GPU** | **Display** | **Connection** | minReplyRedlay | **Mac** | **OS** | **MonitorControl** |
| --- | --- | --- | --- | --- | --- | --- |
| GPU | Screen | Connection | default | Mac | Os | v2.x.x |

GPU
Display
Connection
minReplyRedlay
Mac
OS
MonitorControl

EVGA GeForce GTX 760
Iiyama XUB2792QSU
DisplayPort
default
Hackintosh
10.12
v2.1.0

Writing works out of the box, thanks a lot ! (shows as PL2792Q)
Volume was instant, for brightness to work I had to reboot with the screen connected (probably nvram related).
Read doesn't seem to work at all.
And for easy copy/paste :
| **GPU** | **Display** | **Connection** | minReplyRedlay | **Mac** | **OS** | **MonitorControl** |
| --- | --- | --- | --- | --- | --- | --- |
| GPU | Screen | Connection | default | Mac | Os | v2.x.x |

GPU 	Display 	Connection 	minReplyDelay 	Mac 	OS
AMD Radeon RX 580 8 GB 	Philips 499p9 	DisplayPort 	default 	MacBook Pro (13-inch, 2019) 	Catalina 10.15.7 (19H2)
brightness doesn't work, volume does

everything works for me now on build 721

GPU 	Display 	Connection 	minReplyDelay 	Mac 	OS
AMD Radeon RX 580 8 GB 	Philips 499p9 	DisplayPort 	default 	MacBook Pro (13-inch, 2019) 	Catalina 10.15.7 (19H2)
brightness doesn't work, volume does

everything works for me now on build 721

I'll close this issue as it served its purpose. Individual monitor problems with the new v3.0.0 version and later can be reported in separate issues. Thank you all for the contribution!


FEAT: Support structure_load

Closes: https://github.com/plausible/ecto_ch/issues/37

Thank you for the PR @Zarathustra2 !

No worries, always a pleasure to work with you @ruslandoga