linux 5.2: rare NULL pointer dereference when SteamVR idles

Submitted by Christoph Haag @ChristophHaag

Assigned to Default DRI bug account

Link to original bug (#111139)

Description

Created attachment 144791
dmesg with null pointer dereference

Vega 64, mesa git b68778e6de2, Linux 5.2.

I am relatively sure this started happening with linux 5.2 and that this did not happen on 5.1.

When SteamVR is idle for a while (i.e. the VR headset is not moved), it stops rendering to not waste resources.

When it does this, there is a chance that a kernel bug happens, see attached dmesg.

It does not happen very often, but often enough that I'm relatively sure it started happening with 5.2.

Attachment 144791, "dmesg with null pointer dereference":
dmesg.txt