Wrong colours on some monitors via USB-C to HDMI

[Igor Saggese]

I installed Ubuntu 16.04.1 on my Dell XPS 13 9360 and I'm experiencing some issues with external displays.

I bought two adapters from Aukey: USB-C to VGA and USB-C to HDMI (USB-C is the only port that I can use for video output on my computer).

USB-C to VGA work flawlessly with all display I tested.

USB-C to HDMI has issues with some displays. Sound works great but with some displays (such as on 2 24" Samsung TV monitors) colors are rendered wrong, like if a 16-bit palette is used (this picture posted by another user gives an idea of the problem: https://i.stack.imgur.com/KY44f.jpg).

If I connect the display BEFORE turning it on and then turn it on it works correctly (until any video setting option is changed... then I get weird colours again).
When I get weird colours if I turn the monitor off and on I get correct colours (until a change in video mode options).

However on some other displays it works correctly all the time, such as on a 40" Toshiba TV.

Other users are reporting the same issues with other usb-c to hdmi adapters / monitors combinations.

The same adapter/monitor combination works flawlessly with Windows 10, and previously I used the same monitor with Ubuntu on my old computer (that had HDMI output) with no problems.

I tested some other distros with the same result, so I think it is a kernel-related bug. I tested latest 4.10 rc6 kernel but the problem is still there.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: linux-image-4.8.0-34-generic 4.8.0-34.36~16.04.1
ProcVersionSignature: Ubuntu 4.8.0-34.36~16.04.1-generic 4.8.11
Uname: Linux 4.8.0-34-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.5
Architecture: amd64
CurrentDesktop: Unity
Date: Sun Feb 5 17:39:55 2017
EcryptfsInUse: Yes
InstallationDate: Installed on 2017-02-05 (0 days ago)
InstallationMedia: Ubuntu 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719)
SourcePackage: linux-hwe-edge
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Alin Hanghiuc (alinhan)]

I think I have the same issue:

https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1586787

The colors on the TV look weird the same way that your colors look.

I tried your workaround (restart the TV), and it fixed the colors for me as well. (Thanks!)

Details on my case:

- It happens with two laptops and three Samsung TVs.

- The laptops are a Lenovo ThinkPad T420, and a Fujitsu (I don't have this one near me right now, to give the exact model).

- The Samsung TVs are of different sizes, from different generations (about 4 years apart), one is "smart" (Samsung UE40J5200AW) and the other two are not (I can provide exact models if needed).

- I'm using a DisplayPort to HDMI adapter to connect to the TVs. Actually I've tried multiple models of DP to HDMI adapters and various HDMI cables.

- On both laptops, the issue does not exist when booting from a Linux Mint 17.3 Cinnamon. But it does happen for: Linux Mint 18.1, Ubuntu 14.04 (on which Linux Mint 17.3 is based), Ubuntu 16.04, Ubuntu 16.10, Ubuntu 17.04 (the latest build as of today).

It looks to me that the commonalities for these issues are two: Samsung TVs and recent Linux distros.

[Alin Hanghiuc (alinhan)]

There is another commonality: Intel graphics.

I even tried the Padoka PPA, but the issue was still present.

[Alin Hanghiuc (alinhan)]

I did a new test with another laptop with Intel graphics and Ubuntu 16.04, but which has an HDMI port, connected to one of the three Samsung TVs, and the colors look fine.

Also, for what it's worth, I compared the EDID information (obtained with "get-edid | parse-edid") from this laptop with the one from the T420, and it's identical.

[Giorgio Sironi (giorgiosironi)]

I have just tried Linux Mint 17.3 on a Dell XPS 13 9350 plus a Samsung TV, no difference as the problem is present there too.

[Federico Cupellini (fedecupe)]

It affects me too. Dell XPS 9360, tv is a samsung UE32F57000AW
Cable is usb-c to HDMI AUKEY brand (with a sony bravia TV it works).
Active kernel 4.11.0-14-generic, ubuntu version is 16.04.3 LTS.

This is xrandr output for the samsung monitor
DP1 connected 1920x1080+3200+720 (0x1f6) normal (normal left inverted right x axis y axis) 1060mm x 626mm
 Identifier: 0x44
 Timestamp: 58683937
 Subpixel: unknown
 Gamma: 1.0:1.0:1.0
 Brightness: 1.0
 Clones:
 CRTC: 1
 CRTCs: 0 1 2
 Transform: 1.000000 0.000000 0.000000
             0.000000 1.000000 0.000000
             0.000000 0.000000 1.000000
            filter:
 EDID:
  00ffffffffffff004c2d7a0a00000000
  2e160103804627780aee91a3544c9926
  0f5054bdef80714f81c0810081809500
  a9c0b3000101023a801871382d40582c
  450024724200001e662156aa51001e30
  468f330024724200001e000000fd0018
  4b0f5117000a202020202020000000fc
  0053414d53554e470a20202020200189
  020325f14d901f041305140312202122
  07162309070783010000e2000f67030c
  002000b82d011d80d0721c1620102c25
  8024724200009e011d8018711c162058
  2c250024724200009e011d00bc52d01e
  20b828554024724200001e011d007251
  d01e206e28550024724200001e8c0ad0
  90204031200c4055002472420000182c
 Broadcast RGB: Automatic
  supported: Automatic, Full, Limited 16:235
 audio: auto
  supported: force-dvi, off, auto, on
  1920x1080 (0x1f6) 148.500MHz +HSync +VSync *current +preferred

[Rafael (almeidaraf-gmail)]

I have the same exact problem. I'm running a xps 13 (processor/gpu: intel i7 10510U). I'm using this connector: https://www.dell.com/en-ie/work/shop/dell-adapter-usb-c-to-hdmi-dp-with-power-pass-through/apd/470-aegy/pc-accessories#techspecs_section My monitor is a BenQ EL2870U, I'm using 4K resolution.

My colours are all wrong whenever I dare to change any configuration or if I connect the monitor after boot. It seems to work fine if I boot it already connected.

This is the output of xrandr (while it works fine):

XWAYLAND0 connected 3840x2160+1920+0 (0x24) normal (normal left inverted right x axis y axis) 620mm x 340mm
 Identifier: 0x21
 Timestamp: 14712
 Subpixel: unknown
 Gamma: 1.0:1.0:1.0
 Brightness: 0.0
 Clones:
 CRTC: 0
 CRTCs: 0
 Transform: 1.000000 0.000000 0.000000
             0.000000 1.000000 0.000000
             0.000000 0.000000 1.000000
            filter:
 non-desktop: 0
  supported: 0, 1
  3840x2160 (0x24) 266.750MHz -HSync +VSync *current +preferred
        h: width 3840 start 4056 end 4456 total 5072 skew 0 clock 52.59KHz
        v: height 2160 start 2163 end 2168 total 2192 clock 23.99Hz

[Rafael (almeidaraf-gmail)]

I couldn't find a way to edit my comment above. But I should add that I'm running focal fossa (though the same problem was going on in Bionic Beaver):

rafael@zim:~$ uname -a
Linux zim 5.4.0-51-generic #56-Ubuntu SMP Mon Oct 5 14:28:49 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
rafael@zim:~$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 20.04.1 LTS
Release: 20.04
Codename: focal

[Andrey Shpak (insspb)]

This still exist. Maybe we can help somehow to resolve it?

Linux insspb-kubuntu 5.4.0-89-generic #100-Ubuntu SMP Fri Sep 24 14:50:10 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux

root@insspb-kubuntu:/home/insspb# xrandr
Screen 0: minimum 8 x 8, current 5760 x 2160, maximum 32767 x 32767
HDMI-0 disconnected (normal left inverted right x axis y axis)
eDP-1-1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 344mm x 194mm
   1920x1080 60.02*+ 60.01 59.97 59.96 59.93 48.03
   1680x1050 59.95 59.88
   1600x1024 60.17
   1400x1050 59.98
   1600x900 59.99 59.94 59.95 59.82
   1280x1024 60.02
   1440x900 59.89
   1400x900 59.96 59.88
   1280x960 60.00
   1440x810 60.00 59.97
   1368x768 59.88 59.85
   1360x768 59.80 59.96
   1280x800 59.99 59.97 59.81 59.91
   1152x864 60.00
   1280x720 60.00 59.99 59.86 59.74
   1024x768 60.04 60.00
   960x720 60.00
   928x696 60.05
   896x672 60.01
   1024x576 59.95 59.96 59.90 59.82
   960x600 59.93 60.00
   960x540 59.96 59.99 59.63 59.82
   800x600 60.00 60.32 56.25
   840x525 60.01 59.88
   864x486 59.92 59.57
   800x512 60.17
   700x525 59.98
   800x450 59.95 59.82
   640x512 60.02
   720x450 59.89
   700x450 59.96 59.88
   640x480 60.00 59.94
   720x405 59.51 58.99
   684x384 59.88 59.85
   680x384 59.80 59.96
   640x400 59.88 59.98
   576x432 60.06
   640x360 59.86 59.83 59.84 59.32
   512x384 60.00
   512x288 60.00 59.92
   480x270 59.63 59.82
   400x300 60.32 56.34
   432x243 59.92 59.57
   320x240 60.05
   360x202 59.51 59.13
   320x180 59.84 59.32
DP-1-1 connected 3840x2160+1920+0 (normal left inverted right x axis y axis) 597mm x 336mm
   3840x2160 60.00*+ 60.00 50.00 59.94 30.00 25.00 24.00 29.97 23.98 29.98
   1920x2160 59.99
   2560x1440 59.95
   1920x1080 60.00 50.00 59.94
   1680x1050 59.88
   1280x1024 75.02 60.02
   1440x900 59.90
   1280x960 60.00
   1280x720 60.00 50.00 59.94
   1024x768 75.03 70.07 60.00
   832x624 74.55
   800x600 72.19 75.00 60.32 56.25
   720x576 50.00
   720x480 60.00 59.94
   640x480 75.00 72.81 66.67 60.00 59.94
   720x400 70.08
HDMI-1-1 disconnected (normal left inverted right x axis y axis)
DP-1-2 disconnected (normal left inverted right x axis y axis)
HDMI-1-2 disconnected (normal left inverted right x axis y axis)
DP-1-3 disconnected (normal left inverted...

[Mark Siggers (mhsiggers)]

I have the same problem on Hirsute Hippo. I am on a Lenovo Yoga 730, connecting to a Coms projector from usb-c through a lenovo usb-c to hdmi adapter that was included with the laptop.

I have had no trouble before connecting from the same laptop through the included usb-c to VGA adapter.

I cannot get the colours right even by having the projector connected on boot.

This laptop also has intel graphics.