I came across this bug because of my problem which I described in https://askubuntu.com/questions/1314639/weird-graphics-artifacts- monitor-off-with-ubuntu-20-04-and-nvidia-rtx-5000/1343876#1343876
In my case the Dell monitors tell, they can support 30bit. I came to the conclusion, that the dockingstation's Displayports cannot handle 30bit which leads to strange screen artifacts. However, the HDMI port of the dockingstation outputs 24bits and I have no screen corruption, connecting them directly to laptop is also no problem. In Windows the output is limited at 24bits and the output is reliable. xrandr with "max bpc" 8" is not working me and brings strange errors. Is there any other way to tell Linux system to limit to 24bits? Even before the Desktop appears the console has already switched to 30 bit (according to Monitor OSD info) without any EDID hacking? The Laptop is used daily across different dockingstations with different monitors (Home/Work) System config: - Dell Precision 15" 7540, Xeon E-2286M@2.4GHz, 128 GB ECC RAM, NVIDIA Quadro RTX 5000 16GB VRAM - Dockingstations at Home and offices: WD19DC - Dockingstation 1 WD19DC: 2xDell 43' U4320Q - Dockingstation 2 WD19DC: 2xDellxU3818DW, 37.5" + Laptopdisplay ** Attachment added: "Edid of Dell 43' U4320Q" https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/1890772/+attachment/5502614/+files/edid_U4320Q_Linux.txt -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1890772 Title: No signal on 4K 60Hz DisplayPort monitor by default, until "max bpc" is lowered to 8 Status in gnome-control-center: Unknown Status in HWE Next: New Status in Linux: Unknown Status in Mutter: Unknown Status in OEM Priority Project: New Status in X.Org X server: Unknown Status in linux package in Ubuntu: Confirmed Status in mutter package in Ubuntu: Won't Fix Status in xorg-server package in Ubuntu: Invalid Bug description: The bug is originated from, https://bugs.launchpad.net/somerville/+bug/1887915/ https://bugs.launchpad.net/somerville/+bug/1886778 It has some problem when user connect to external 4K monitor with refresh rate 60. The problem can be solved by lower the bpc, or lower the refresh rate. `xrandr --output DP-3 --set "max bpc" 8` Would like to open this bug to open discussion for enhancing user experience. existed upstream bug: - https://gitlab.freedesktop.org/drm/intel/-/issues/1890 --- ProblemType: Bug ApportVersion: 2.20.11-0ubuntu27.4 Architecture: amd64 BootLog: Error: [Errno 13] Permission denied: '/var/log/boot.log' CasperMD5CheckResult: skip CompositorRunning: None CurrentDesktop: ubuntu:GNOME DistUpgraded: Fresh install DistributionChannelDescriptor: # This is the distribution channel descriptor for the OEM CDs # For more information see http://wiki.ubuntu.com/DistributionChannelDescriptor canonical-oem-somerville-focal-amd64-20200502-85+fossa-samwell-tgl+X42 DistroCodename: focal DistroRelease: Ubuntu 20.04 DistroVariant: ubuntu DkmsStatus: nvidia, 440.100, 5.6.0-1021-oem, x86_64: installed ExtraDebuggingInterest: Yes GraphicsCard: Intel Corporation Device [8086:9a49] (rev 01) (prog-if 00 [VGA controller]) Subsystem: Dell Device [1028:09fc] Subsystem: Dell GP107M [GeForce MX350] [1028:09fc] InstallationDate: Installed on 2020-08-07 (0 days ago) InstallationMedia: Ubuntu 20.04 "Focal" - Build amd64 LIVE Binary 20200502-05:58 Package: xorg 1:7.7+19ubuntu14 [origin: unknown] PackageArchitecture: amd64 ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.6.0-1021-oem root=UUID=41be2253-410a-4ef7-a096-4193a58efdbd ro quiet splash vt.handoff=7 ProcVersionSignature: Ubuntu 5.6.0-1021.21-oem 5.6.19 Tags: third-party-packages focal ubuntu Uname: Linux 5.6.0-1021-oem x86_64 UnreportableReason: This is not an official Ubuntu package. Please remove any third party package and try again. UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo _MarkForUpload: True version.compiz: compiz N/A version.libdrm2: libdrm2 2.4.101-2 version.libgl1-mesa-dri: libgl1-mesa-dri 20.0.8-0ubuntu1~20.04.1 version.libgl1-mesa-glx: libgl1-mesa-glx N/A version.xserver-xorg-core: xserver-xorg-core 2:1.20.8-2ubuntu2.2 version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:19.1.0-1 version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20200226-1 version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.16-1 To manage notifications about this bug go to: https://bugs.launchpad.net/gnome-control-center/+bug/1890772/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
