Somewhere between 5.1 and amd-staging-drm-next for 5.2-rc1, I stopped being able to set my Acer XV272U 144Hz 1440p display in its 144Hz setting at 2560x1440 resolution. 1920x1080@144Hz still works. This only happens under the display core driver. Setting amdgpu.dc=0 fixes it, but that is not needed on the 5.1 kernel. I will bisect tonight when I get home and have access to my AMD card. Card: XFX RX 590 Kernel: current AMD-staging-drm-next HEAD. The issue occurs both in Xfce4, and in sway (wayland), so I’m assuming that the desktop environment has little to do with the issue. Sorry for bad formatting on mobile, I wanted to get this in and filed with the 5.2 release coming up.
My guess is that this is probably related to the: https://patchwork.freedesktop.org/patch/306397/ patch. It might not be defaulting to 8bpc as the maximum, limiting you to 120Hz at 1440p.
This patch should fix it: https://patchwork.freedesktop.org/patch/308794/
Thanks. I will test tonight with the patch applied when I have access to an AMD card.
I just tested this now on my setup with this patch on top of amd-staging-drm-next, and all looks good! Thank you kindly. Too bad this one was easy enough that I didn't get to do any learning. Now, on to the power management issues I see under load :).
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