flickering and visual artifacts when using display port with display stream compression
I have 6 x 4k monitors with 2 sets of 2 on single display ports with splitters the other two on a DP and HDMI port (4 ports in use - 1 HDMI and 3 DP). In order to achieve 4k @ 60fps on both monitors in the pair display stream compression is required and did not work until the last few kernels. By that I mean when I attempted to enable the 2nd monitor in a pair at 60 fps it would fail, but would succeed at 30 with the first always at 60. The more recent kernels (not 100% sure on when, but at least the last 2-3) I can enable the second monitor in a pair at 60 fps, but then I see flickering (completely black for around a second) and artifacts. Sometimes worse than others to the point of being unusable. The flickering only occurs on the first of the two monitors in either pair (at least when set to 60fps on first and 30fps on second).
My workaround has been to to keep one monitor in each pair at 30 fps, but as of 5.19.12 it seems to always happen. I see nothing interesting in systemd journal, dmesg, etc.
Two things,
- Is there a way to disable DSC to see a) verify that is the problem, and b) workaround the issue?
- What other logs or debugging information can I provide that might be useful?
info
Videos are of first monitor in a pair.