Created attachment 131892 [details]
The /sys/class/drm/card0/error report.

Playing Portal 2 for a few minutes causes the following symptoms:

- Audio loops last ~0.5 seconds for ~30 seconds, and then the game crashes
- The log includes the line:
"intel_do_flush_locked failed: Input/output error"
- dmesg includes the following message:

[  192.808861] [drm] GPU HANG: ecode 9:0:0x85dffffb, in portal2_linux [2144], reason: Hang on render ring, action: reset
[  192.808863] [drm] GPU hangs can indicate a bug anywhere in the entire gfx stack, including userspace.
[  192.808864] [drm] Please file a _new_ bug report on bugs.freedesktop.org against DRI -> DRM/Intel
[  192.808865] [drm] drm/i915 developers can then reassign to the right component if it's not a kernel issue.
[  192.808866] [drm] The gpu crash dump is required to analyze gpu hangs, so please always attach it.
[  192.808868] [drm] GPU crash dump saved to /sys/class/drm/card0/error
[  192.808933] drm/i915: Resetting chip after gpu hang
[  192.809191] [drm] GuC firmware load skipped
[  194.823828] [drm] RC6 on

This prompted me to file this bug report. Attached is the GPU crash dump. There are some indications (https://github.com/ValveSoftware/portal2/issues/278) that this issue may only be present in versions of mesa after a certain point.

Thank you for your help, and let me know if I can provide further diagnostic assistance.