[DC][bisected] Random screen locks on RX460

Submitted by Nikola Forró

Assigned to Default DRI bug account

Link to original bug (#101001)

Description

Created attachment 131314
dmesg

I'm using the latest code from amd-staging-4.9 branch of ~agd5f/linux.

The screen locks are happening randomly when playing videos (in browser or with mplayer) or when running commands that output a lot of text in xterm.
When it happens, contents of the screen are no longer refreshed, except for mouse pointer.

Following errors are reported:

[drm:drm_atomic_helper_commit_cleanup_done] ERROR [CRTC:38:crtc-0] flip_done timed out
[drm:dc_commit_surfaces] ERROR dm_dc_surface_commit: acrtc 0, already busy

My reproducer is to fill the screen with two xterm windows next to each other and generate random lines of text in both of them, using command like this for example:

tr -dc a-z1-4 </dev/urandom | tr 1-2 ' \n' | awk 'length==0 || length>50' | tr 3-4 ' ' | sed 's/^ *//' | cat -s | sed 's/ / /g' | fmt

It usually takes just a couple of minutes for the screen lock to happen.

I've bisected the issue to this commit:

https://cgit.freedesktop.org/~agd5f/linux/commit/?h=amd-staging-4.9&id=afbeb2d0961b2139bcf6553a710e6a8ae5d09d34

Attachment 131314, "dmesg":
dmesg