No error state with CONFIG_DRM_I915_PREEMPT_TIMEOUT != 0
When the kernel is built with CONFIG_DRM_I915_PREEMPT_TIMEOUT=640, I see "Ressetting RCS for preemption time out". But there is no error state collected. If I change that config to 0, disabling the preemption timer, then I see an actual GPU hang, complete with error state.
It seems like the GPU hang is tripping the preemption-timeout before it's tripping the hang-check timeout, and error state is only recorded for the latter.
I am seeing this on
ac5e57322614f1c08b00ed9f52153ca12603c637 (drm-tip: 2019y-12m-05d-15h-33m-49s UTC integration manifest).