[nouveau] Pixel pattern error at 120Hz or 144Hz, but 60Hz works (monitor MSI Optix G24C / model 1462)

[Shahar Or]

The primary monitor, Microstep 24", is capable of 144 Hz refresh rate and I do use that regularly in Windows 10.

When I set the rate to anything higher than 60 Hz (120 or 144) I get a wrong pixel pattern. See attached photos.

ProblemType: Bug
DistroRelease: Ubuntu 19.10
Package: xorg 1:7.7+19ubuntu12
ProcVersionSignature: Ubuntu 5.3.0-19.20-generic 5.3.1
Uname: Linux 5.3.0-19-generic x86_64
ApportVersion: 2.20.11-0ubuntu8.2
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: None
CurrentDesktop: ubuntu:GNOME
Date: Tue Nov 12 12:06:45 2019
DistUpgraded: 2019-10-23 22:37:24,432 DEBUG Running PostInstallScript: './xorg_fix_proprietary.py'
DistroCodename: eoan
DistroVariant: ubuntu
DkmsStatus: virtualbox, 6.0.14, 5.3.0-19-generic, x86_64: installed
ExtraDebuggingInterest: Yes, including running git bisection searches
GraphicsCard:
 NVIDIA Corporation GP102 [GeForce GTX 1080 Ti] [10de:1b06] (rev a1) (prog-if 00 [VGA controller])
   Subsystem: eVga.com. Corp. GP102 [GeForce GTX 1080 Ti] [3842:6390]
InstallationDate: Installed on 2010-10-12 (3317 days ago)
InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Release amd64 (20101007)
MachineType: Supermicro X10SRA
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-5.3.0-19-generic root=/dev/mapper/root ro quiet splash vt.handoff=7
SourcePackage: xorg
UpgradeStatus: Upgraded to eoan on 2019-10-23 (19 days ago)
dmi.bios.date: 06/23/2016
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 2.0a
dmi.board.asset.tag: Default string
dmi.board.name: X10SRA
dmi.board.vendor: Supermicro
dmi.board.version: 1.01
dmi.chassis.asset.tag: Default string
dmi.chassis.type: 17
dmi.chassis.vendor: Supermicro
dmi.chassis.version: 0123456789
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr2.0a:bd06/23/2016:svnSupermicro:pnX10SRA:pvr0123456789:rvnSupermicro:rnX10SRA:rvr1.01:cvnSupermicro:ct17:cvr0123456789:
dmi.product.family: Default string
dmi.product.name: X10SRA
dmi.product.sku: Default string
dmi.product.version: 0123456789
dmi.sys.vendor: Supermicro
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.99-1ubuntu1
version.libgl1-mesa-dri: libgl1-mesa-dri 19.2.1-1ubuntu1
version.libgl1-mesa-glx: libgl1-mesa-glx 19.2.1-1ubuntu1
version.xserver-xorg-core: xserver-xorg-core 2:1.20.5+git20191008-0ubuntu1
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.10.6-1
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:19.0.1-1ubuntu1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20190815-1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.16-1
xserver.bootTime: Sun May 13 18:05:25 2018
xserver.configfile: default
xserver.errors:
 [drm] Failed to open DRM device for pci:0000:03:00.0: -19
 open /dev/dri/card0: No such file or directory
 open /dev/dri/card0: No such file or directory
 Screen 0 deleted because of no matching config section.
 AIGLX: reverting to software rendering
xserver.logfile: /var/log/Xorg.0.log
xserver.outputs:

xserver.version: 2:1.19.6-1ubuntu4

[Shahar Or (mightyiam)]

Here's a photo of the incorrect pixel pattern. From normal viewing distance it's barely usable. Certainly not tolerable.

[Daniel van Vugt (vanvugt)]

Sorry I can't see a problem in that screenshot. Can you provide more?

[Shahar Or (mightyiam)]

I don't feel that a non-close-up photo could help, but here is one. From a normal viewing distance, when higher than 60hz, the image seems to have decreased brightness. Only on close up one can tell that it does not appear to be brightness, but a wrong pixel pattern.

[Daniel van Vugt (vanvugt)]

One interesting observation is that your logs are saying that 60Hz is the preferred native mode of the monitor:

[ 1165.229] (II) modeset(0): First detailed timing is preferred mode
[ 1165.229] (II) modeset(0): Preferred mode is native pixel format and refresh rate
...
[ 1165.229] (II) modeset(0): Printing probed modes for output DP-1
[ 1165.229] (II) modeset(0): Modeline "1920x1080"x60.0 148.50 1920 2008 2052 2200 1080 1084 1089 1125 +hsync +vsync (67.5 kHz eP)
[ 1165.229] (II) modeset(0): Modeline "1920x1080"x144.0 356.39 1920 2008 2052 2200 1080 1084 1089 1125 +hsync +vsync (162.0 kHz e)
[ 1165.229] (II) modeset(0): Modeline "1920x1080"x120.0 297.00 1920 1968 2000 2200 1080 1083 1088 1125 +hsync +vsync (135.0 kHz e)
...

Which is also shown in this list:

  1920x1080 (0x48) 148.500MHz +HSync +VSync *current +preferred
        h: width 1920 start 2008 end 2052 total 2200 skew 0 clock 67.50KHz
        v: height 1080 start 1084 end 1089 total 1125 clock 60.00Hz
  1920x1080 (0x49) 356.390MHz +HSync +VSync
        h: width 1920 start 2008 end 2052 total 2200 skew 0 clock 162.00KHz
        v: height 1080 start 1084 end 1089 total 1125 clock 144.00Hz
  1920x1080 (0x4a) 297.000MHz +HSync +VSync
        h: width 1920 start 1968 end 2000 total 2200 skew 0 clock 135.00KHz
        v: height 1080 start 1083 end 1088 total 1125 clock 120.00Hz

So it sounds like this might be a hardware limitation. Maybe it's changing something unusual to go above 60Hz and maybe just the Windows 10 driver is better at handling that, whatever it is.

If this is a software bug then it should probably be assigned to the Linux kernel or Xorg modeset driver. Because the details of the pixel layout are only known and controllable there.

[Daniel van Vugt (vanvugt)]

Does the problem occur if you log into 'Ubuntu on Wayland' ?

[Daniel van Vugt (vanvugt)]

I can see a couple of pixel-layout-related settings here:

 dithering depth: auto
  supported: auto, 6 bpc, 8 bpc
 dithering mode: auto
  supported: auto, off, static 2x2, dynamic 2x2, temporal

The nouveau kernel driver provides them regardless of the attached monitor. You can tweak them with:

  xrandr --output DP-1 --set <property> <value>

or similar. Though that might not help...

What might help is installing the proprietary Nvidia driver instead. Have a look in:

  Software & Updates > Additional Drivers

to install the Nvidia driver.

[Shahar Or (mightyiam)]

Thank you for following up, Daniel.

Same in an Ubuntu on Wayland session.

I tried setting dithering depth and dithering mode but it doesn't change.

Should this be reported upstream?

[Daniel van Vugt (vanvugt)]

No we don't yet know what project to report any bug to "upstream".

Next please install the Nvidia driver via:

  Software & Updates > Additional Drivers

[Shahar Or (mightyiam)]

Thank you for following up, Daniel.

With the NVIDIA driver, the login screen doesn't show up.

What would be the appropriate next step, please?

[Daniel van Vugt (vanvugt)]

Thanks. That's a different bug but I don't want to dwell on it here. Please try editing /etc/gdm3/custom.conf and uncommenting the line:

  #WaylandEnable=false

If that gets you the login screen then please tell us if this bug is still an issue.

If that doesn't get you the login screen then please open a new bug about the Nvidia driver breaking the login screen.

[Shahar Or (mightyiam)]

Thank you for the instructions, Daniel.

I did uncomment the above line using sudoedit, installed nvidia-driver-435 and rebooted.

No apparent change. Still no login screen.

Reported:

https://bugs.launchpad.net/ubuntu/+source/nvidia-graphics-drivers-435/+bug/1856507

Can progress be made on this in parallel to the nvidia-driver-435 bug, please?

[Daniel van Vugt (vanvugt)]

Unless we can diagnose and fix/workaround bug 1856507 quickly then I am out of ideas for now.

[Daniel van Vugt (vanvugt)]

I would like to mention the exact monitor model in the bug description but don't have a clear answer for that:

[ 1165.229] (II) modeset(0): Manufacturer: MSI Model: 1462 Serial#: 1
[ 1165.229] (II) modeset(0): Year: 2018 Week: 16

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This change was made by a bot.

[Shahar Or (mightyiam)]

It seems that I am able to set the refresh rate to 120Hz and 144Hz.

Feel free to close this.

xserver-xorg-video-nouveau 1:1.0.16-1

Linux shahar-desktop 5.3.0-46-generic #38-Ubuntu SMP Fri Mar 27 17:37:05 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 19.10
Release: 19.10
Codename: eoan

[Daniel van Vugt (vanvugt)]

Is the "pixel pattern error" gone?

[Shahar Or (mightyiam)]

Yes, Daniel. The picture is normal at all available rates above 60Hz. 120Hz and 144Hz. Awesome.

[Daniel van Vugt (vanvugt)]

Great!

[Shahar Or (mightyiam)]

Update: in the motherboard settings, under I/O, there's an option "Video Option ROM Type". This bug occurs when the value is set to UEFI. When the value is set to Legacy, the bug does not occur. There's a third possible value, "Disabled" or similar, which I did not try.

Excuse me ignorance. I know the value of a LAN adapter option ROM — booting from network. But what is the value of a video card option ROM, please? And since this motherboard does not have an integrated video card, what does this option pertain to, please?

[Daniel van Vugt (vanvugt)]

I would guess that option exposes DOS-era VGA support, which is still used by operating systems before they boot. While that shouldn't affect the operation of Linux after it has booted, it might, if it changes the default dithering mode on the hardware and Linux doesn't change it after that.

Now I'm guessing too much.