I am using Fedora 35 with KDE on an AMD 5800x and AMD 6800XT with a LG 27GP850-B 27 monitor. When I installed this with the Gnome desktop installer everything was working correctly. I recently decided to change to XFCE, before then switching to KDE and I followed Switching desktop environments :: Fedora Docs and everything worked correctly after switching to XFCE and then to KDE and finally removing Gnome.
Unfortunately the last 2 kernel upgrades, kernel-5.16.7-200.fc35.x86_64 and kernel-5.16.5-200.fc35.x86_64, have made my system unable to detect my monitors native resolutions. The kernels prior to this, e.g. kernel-5.15.18-200.fc35.x86_6, detect them just fine. This is what xrandr displays when using kernel-5.15.18-200.fc35.x86_6
Screen 0: minimum 320 x 200, current 2560 x 1440, maximum 16384 x 16384
DisplayPort-0 disconnected (normal left inverted right x axis y axis)
DisplayPort-1 disconnected (normal left inverted right x axis y axis)
DisplayPort-2 connected primary 2560x1440+0+0 (normal left inverted right x axis y axis) 697mm x 392mm
2560x1440 164.96*+ 143.97 + 120.00 99.95 59.95
1920x1200 164.96
1920x1080 120.00 100.00 119.88 60.00 60.00 50.00 59.94
1600x1200 164.96
1680x1050 164.96
1280x1024 164.96
1440x900 164.96
1280x800 164.96
1280x720 60.00 50.00 59.94
1024x768 60.00
800x600 60.32
720x480 60.00 59.94
640x480 60.00 59.94
HDMI-A-0 disconnected (normal left inverted right x axis y axis)
This is what xrandr displays when using kernel-5.16.7-200.fc35.x86_64 or kernel-5.16.5-200.fc35.x86_64
Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 16384 x 16384
DisplayPort-0 disconnected (normal left inverted right x axis y axis)
DisplayPort-1 disconnected (normal left inverted right x axis y axis)
DisplayPort-2 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 697mm x 392mm
1920x1080 60.00 60.00* 50.00 59.94
1280x720 60.00 50.00 59.94
1024x768 60.00
800x600 60.32
720x480 60.00 59.94
640x480 60.00 59.94
HDMI-A-0 disconnected (normal left inverted right x axis y axis)
I’ve tried to use my saved profile in autorandr but it fails with:
Failed to apply profile 'blindcant@1440p' (line 930):
Command failed: xrandr --fb 2560x1440 --output DisplayPort-2 --crtc 0 --gamma 1.0:1.0:1.0 --mode 2560x1440 --pos 0x0 --primary --rate 164.96 --reflect normal --rotate normal --set max bpc 8 --set non-desktop 0 --set scaling mode None --set TearFree auto --set underscan off --set underscan hborder 0 --set underscan vborder 0 (line 930)
And this is the profile that works fine when all kernels prior to 5.16.*.
This is my first AMD GPU and I have no X11 configuration for it like I’ve had for NVIDIA GPUs in the past. Currently I am booting into kernel-5.15.18-200.fc35.x86_6 so I can use the correct resolution but I would like to find a solution so I don’t have to stick with this kernel. What can I do to try and troubleshoot this issue?
If you actually removed gnome it may have something to do with the issue. The default fedora workstation has gnome portions deeply tied into the display functions.
The default window manager for fedora 35 is wayland. I think that applies with all the systems now that the nvidia driver mostly supports wayland. You did not say whether you are using wayland or xorg, but it could also be a factor.
For an AMD GPU there are 2 possible drivers, amdgpu and radeon. Which are you using?
Please post the output of inxi -Fzx so we can see the actual hardware and drivers in use.
Yes I did actually remove Gnome after switching the display manager from gdm to sddm and confirmed it was working. Interesting that switching desktops may be the reason for this, I did the switch about 2 weeks ago and I feel I would have upgraded the kernel before encountering this issue which started about a week ago. Obviously I’d prefer not to reinstall with the KDE spin but if it comes to that I can. I also have i3 installed as well but rarely use it. My resolution issues start from the LUKS password screen (I think that is plymouth?) and persist all the way through to sddm and KDE.
Sorry forgot to mention I am using xorg, I have never been able to get Wayland working with my current AMD GPU. When choosing Wayland from sddm the screen goes black and does nothing, before falling back to the sddm login page.
I don’t recall installing any drivers, so it must be bundled with the kernel. Not sure which one?
I didn’t have inxi installed, so I’ve installed and ran it as root. Here is the output.
I also have a KVM switch ( https://www.lindy.com.au/2-port-dp-1-2-usb-2-0-audio-cable-kvm-switch ) which is Display Port 1.2 compatible which supports my target resolution of 1440p at 165hz. I don’t think this is the problem because the resolution and refresh rate are working correctly in 5.15.18-200.fc35.x86_64 with or without the KVM. I haven’t tested without the KVM on the new kernels though as I didn’t think it was necessary.
If booting from an older kernel works (and that’s the only difference), then it’s likely a kernel driver issue. You can report issues for the amdgpu drivers at
I concur with @qulogic . With the 5.15 kernel it works properly and with the 5.16 kernel it does not so it seems related to either the kernel or the driver and a bug should be filed. I would report it against the amdgpu driver as suggested, but also against the kernel at https://bugzilla.redhat.com/post_bug.cgi
I had time to reinstall Fedora using the KDE spin and the kernel that comes with that, 5.14.10-300.fc35.x86_64, is working fine. I upgraded the system and the latest kernel from that update, kernel-5.16.9-200.fc35.x86_64, is still broken with the same issue. I haven’t heard from any one yet one the bug tickets that I’ve raised.
EDIT: I manually reinstalled 5.15.18-200.fc35.x86_64 and it is working correctly.
Not sure why this would make a difference when every kernel under 5.15.18-200.fc35.x86_64 worked with and without the KVM. I literally reinstalled today from a KDE spin and the kernel in the KDE spin worked, then after a system upgrade the latest one didn’t work. I also just manually reinstalled 5.15.18-200.fc35.x86_64 and it works as well. That makes me think it is a driver issue rather than a KVM hardware issue.
You could be onto something here as someone commented on the AMD bug, they have a KVM and the KVM was indeed the issue. They have a DP 1.4 KVM and I have a DP 1.2 KVM and apparently kernel 5.16 introduced DP 2 support. I will try loading the latest kernel without the KVM tomorrow when I have some time.
EDIT:
@oprizal yes you were right, it is the KVM that is a part of the problem. So I just manually installed kernel-5.16.1-200.fc35.x86_64 and booted into that with the KVM and the resolution issue I described is there. When removing the KVM and booting to kernel-5.16.1-200.fc35.x86_64 again my resolution is detected correctly, although I have to fix this manually with my autorandr profile.
This behaviour is consistent with what the other user on the AMD bug described and the developers over there thought this could be a regression with the EDID being processed through the KVM. I also did the same test with kernel-5.16.9-200.fc35.x86_64 and had the same result. My next steps are going to be to try and do bug bisect ( https://www.kernel.org/doc/html/latest/admin-guide/bug-bisect.html ) between 5.15.18-200 and 5.16.1-200. 5.15.18-200 is when the resolution through the KVM is last working and 5.16.1-200is when the resolution through the KVM isn’t working.
I’ve been offline with life for a while. I upgraded to Fedora 36 (still KDE spin) today and my issue is gone with 5.17.6-300.fc36.x86_64, I’ve updated the other bug tickets.