Screen flickering with 4K display(s) and Navi
GPU: ASRock RX 5700 XT Challenger D 8G OC
CPU: IBM POWER9 8-core
Distro: Void Linux ppc64le
Kernel: 5.4.2
Mesa: 20-git + LLVM 10-git
Display(s): 3x LG 27UD69P-W
Desktop: Xfce
Could be related to #234 (closed). I got a Navi card a few days ago, patched my kernel with #984 (closed) in order to get DC support, and it ran fine for a couple days, and then suddenly started flickering, now it happens always.
The flickering is significant when I run a compositor. When I don't, it only generally flickers when windows move (but not too much when the actual contents of windows change, e.g. when playing a video).
I can work around the issue by doing:
echo high > /sys/class/drm/card0/device/power_dpm_force_performance_level
Alternatively, low
also works, but is a tad slow, so it seems the issue is related to power management and specifically clocks like the other ones. When changing from low to high or high to low, I notice a short flicker, but only once.
Here's a video after switching to auto
: https://i.imgur.com/l8nRRVL.mp4 (at the end I switch back to high
and you can see it stops)
Unplugging or turning off the other two displays doesn't make the issue stop. It also seems unrelated to the 75Hz problem, as these displays run at 60Hz.
Let me know if you need any more information. I'm also open to trying any patches.