Apple displays need to be excluded from -d list about ddcctl

[kfix]

brightness:

$ ddcctl -d 1 -b ?
2016-09-26 08:27:06.866 ddcctl[12679:1651599] D: NSScreen #724066636 (1200x1920) DPI is 94.00
2016-09-26 08:27:06.868 ddcctl[12679:1651599] D: NSScreen #458652801 (2560x1080) DPI is 112.00
2016-09-26 08:27:06.868 ddcctl[12679:1651599] I: found 2 displays
2016-09-26 08:27:06.868 ddcctl[12679:1651599] I: polling display 1's EDID
VN:4268 PN:41148 SN:810241612 UN:0 IN:14087 NVDATesla IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/IXVE@10/IOPP/IGPU@0/NVDA,Display-A@0/NVDATesla/display0/AppleDisplay-Portrait
2016-09-26 08:27:06.894 ddcctl[12679:1651599] D: command arg-pair: d: 1
2016-09-26 08:27:06.895 ddcctl[12679:1651599] D: command arg-pair: b: ?
2016-09-26 08:27:06.895 ddcctl[12679:1651599] D: querying VCP control: #16 =?
VN:4268 PN:41148 SN:810241612 UN:0 IN:14879 NVDATesla IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/IXVE@10/IOPP/IGPU@0/NVDA,Display-A@0/NVDATesla/display0/AppleDisplay-Portrait
VN:4268 PN:41148 SN:810241612 UN:0 IN:16967 NVDATesla IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/IXVE@10/IOPP/IGPU@0/NVDA,Display-A@0/NVDATesla/display0/AppleDisplay-Portrait
2016-09-26 08:27:07.211 ddcctl[12679:1651599] I: VCP control #16 = current: 75, max: 100

contrast:

$ ddcctl -d 1 -c ?
2016-09-26 08:27:13.167 ddcctl[12688:1651668] D: NSScreen #724066636 (1200x1920) DPI is 94.00
2016-09-26 08:27:13.168 ddcctl[12688:1651668] D: NSScreen #458652801 (2560x1080) DPI is 112.00
2016-09-26 08:27:13.169 ddcctl[12688:1651668] I: found 2 displays
2016-09-26 08:27:13.169 ddcctl[12688:1651668] I: polling display 1's EDID
VN:4268 PN:41148 SN:810241612 UN:0 IN:14087 NVDATesla IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/IXVE@10/IOPP/IGPU@0/NVDA,Display-A@0/NVDATesla/display0/AppleDisplay-Portrait
2016-09-26 08:27:13.204 ddcctl[12688:1651668] D: command arg-pair: d: 1
2016-09-26 08:27:13.205 ddcctl[12688:1651668] D: command arg-pair: c: ?
2016-09-26 08:27:13.205 ddcctl[12688:1651668] D: querying VCP control: #18 =?
VN:4268 PN:41148 SN:810241612 UN:0 IN:14879 NVDATesla IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/IXVE@10/IOPP/IGPU@0/NVDA,Display-A@0/NVDATesla/display0/AppleDisplay-Portrait
VN:4268 PN:41148 SN:810241612 UN:0 IN:16967 NVDATesla IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/IXVE@10/IOPP/IGPU@0/NVDA,Display-A@0/NVDATesla/display0/AppleDisplay-Portrait
2016-09-26 08:27:13.520 ddcctl[12688:1651668] I: VCP control #18 = current: 75, max: 100

[mathew-kurian]

26 10:06:24.327 ddcctl[47466:6405214] E: Failed to send DDC command!

[kfix]

@bluejamesbond I cannot remotely debug your monitor, much less with one line of output.

[kfix]

Copy back make displaylist framebuffers

[mathew-kurian]

https://gist.github.com/bluejamesbond/222f24afa18ead96abba89774f88e595

ddcctl mkurian$ ddcctl -d 2 -b ?

2016-09-26 10:30:08.721 ddcctl[48093:6424632] D: NSScreen #69731906 (1440x900) DPI is 110.50
2016-09-26 10:30:08.722 ddcctl[48093:6424632] D: NSScreen #724054419 (1920x1200) DPI is 94.00
2016-09-26 10:30:08.722 ddcctl[48093:6424632] I: found 2 displays
2016-09-26 10:30:08.722 ddcctl[48093:6424632] I: polling display 2's EDID
VN:4268 PN:40983 SN:825504851 UN:3 IN:14087 NVDA IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/P0P2@1/IOPP/GFX0@0/NVDA,Display-B@1/NVDA/display0/AppleDisplay
2016-09-26 10:30:08.752 ddcctl[48093:6424632] D: command arg-pair: d: 2
2016-09-26 10:30:08.752 ddcctl[48093:6424632] D: command arg-pair: b: ?
2016-09-26 10:30:08.752 ddcctl[48093:6424632] D: querying VCP control: #16 =?
VN:4268 PN:40983 SN:825504851 UN:3 IN:16907 NVDA IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/P0P2@1/IOPP/GFX0@0/NVDA,Display-B@1/NVDA/display0/AppleDisplay
VN:4268 PN:40983 SN:825504851 UN:3 IN:16727 NVDA IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/P0P2@1/IOPP/GFX0@0/NVDA,Display-B@1/NVDA/display0/AppleDisplay
2016-09-26 10:30:09.069 ddcctl[48093:6424632] E: DDC send command failed!
2016-09-26 10:30:09.069 ddcctl[48093:6424632] E: VCP control #16 = current: 110, max: 128

[kfix]

This program is not for apple displays!

[mathew-kurian]

This is a dell monitor I am connected to. Everything works except "read"

[kfix]

Ok, I see that Dell on the 2nd display...how is the monitor connected?
Could you please include a full dump of ddcctl read attempt into this issue?

[mathew-kurian]

I included that at the bottom I believe. Let me know if you need more. It's connected via DVI and through display port adapter. Same issue happened with an LG which was connected via display port directly.

[kfix]

@bluejamesbond you never posted the full output of ddcctl

[mathew-kurian]

What command do you want me to run?

ddcctl mkurian$ ddcctl -d 1 -b ?

2016-09-26 23:01:43.476 ddcctl[37839:1146076] D: NSScreen #458677808 (1920x1080) DPI is 81.50
2016-09-26 23:01:43.476 ddcctl[37839:1146076] I: found 1 displays
2016-09-26 23:01:43.476 ddcctl[37839:1146076] I: polling display 1's EDID
VN:7789 PN:23305 SN:72815 UN:4 IN:14855 NVDA IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/P0P2@1/IOPP/GFX0@0/NVDA,Display-C@2/NVDA/display0/AppleDisplay
2016-09-26 23:01:43.488 ddcctl[37839:1146076] D: command arg-pair: d: 1
2016-09-26 23:01:43.488 ddcctl[37839:1146076] D: command arg-pair: b: ?
2016-09-26 23:01:43.488 ddcctl[37839:1146076] D: querying VCP control: #16 =?
VN:7789 PN:23305 SN:72815 UN:4 IN:16427 NVDA IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/P0P2@1/IOPP/GFX0@0/NVDA,Display-C@2/NVDA/display0/AppleDisplay
VN:7789 PN:23305 SN:72815 UN:4 IN:17003 NVDA IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/P0P2@1/IOPP/GFX0@0/NVDA,Display-C@2/NVDA/display0/AppleDisplay
2016-09-26 23:01:43.801 ddcctl[37839:1146076] E: DDC send command failed!
2016-09-26 23:01:43.801 ddcctl[37839:1146076] E: VCP control #16 = current: 0, max: 0

ddcctl mkurian$ ddcctl -d 1 -c ?

2016-09-26 23:02:23.484 ddcctl[37869:1151933] D: NSScreen #458677808 (1920x1080) DPI is 81.50
2016-09-26 23:02:23.484 ddcctl[37869:1151933] I: found 1 displays
2016-09-26 23:02:23.484 ddcctl[37869:1151933] I: polling display 1's EDID
VN:7789 PN:23305 SN:72815 UN:4 IN:14855 NVDA IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/P0P2@1/IOPP/GFX0@0/NVDA,Display-C@2/NVDA/display0/AppleDisplay
2016-09-26 23:02:23.497 ddcctl[37869:1151933] D: command arg-pair: d: 1
2016-09-26 23:02:23.497 ddcctl[37869:1151933] D: command arg-pair: c: ?
2016-09-26 23:02:23.497 ddcctl[37869:1151933] D: querying VCP control: #18 =?
VN:7789 PN:23305 SN:72815 UN:4 IN:16683 NVDA IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/P0P2@1/IOPP/GFX0@0/NVDA,Display-C@2/NVDA/display0/AppleDisplay
VN:7789 PN:23305 SN:72815 UN:4 IN:17259 NVDA IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/P0P2@1/IOPP/GFX0@0/NVDA,Display-C@2/NVDA/display0/AppleDisplay
2016-09-26 23:02:23.809 ddcctl[37869:1151933] E: DDC send command failed!
2016-09-26 23:02:23.809 ddcctl[37869:1151933] E: VCP control #18 = current: 15, max: 0

ddcctl -d ?

016-09-26 23:02:49.775 ddcctl[37891:1155406] D: NSScreen #458677808 (1920x1080) DPI is 81.50
2016-09-26 23:02:49.775 ddcctl[37891:1155406] I: found 1 displays
2016-09-26 23:02:49.775 ddcctl[37891:1155406] Usage:
 ddcctl -d <1-..> [display#]
    -w 100000 [delay usecs between settings]
----- Basic settings -----
    -b <1-..> [brightness]
    -c <1-..> [contrast]
----- Settings that don't always work -----
    -m <1|2> [mute speaker OFF/ON]
    -v <1-254> [speaker volume]
    -i <1-12> [select input source]
    -p <1|2-5> [power on | standby/off]
    -o [read-only orientation]
----- Setting grammar -----
 -X ? (queries setting X)
 -X NN (setting X to NN)
 -X <NN>- (decreases setting X by NN)
 -X <NN>+ (increases setting X by NN)

[kfix]

try ddcctl -d 2 -b ?

[mathew-kurian]

@kfix ddcctl -d 1 is actually hitting the external monitor. the macbook is closed atm and only the external display is on

PS. Your library is being used here https://github.com/bluejamesbond/MonitorControl.OSX

[kfix]

There have been some nice contributions to fix ddcctl.
Please give master a pull & rebuild to see if they fix your issue.

[mathew-kurian]

Thanks for following up. I give a pull this weekend

[kfix]

I've made ddcctl bypass built-in displays in a4792bb, but they are still in the count for -d.
Perhaps it would be better if they were not in the count at all, so that the same commands would work whether the lid was shut or open.