[Intel-gfx] [PATCH 0/8] drm/i915: PREEMPT_RT related fixups.

Sebastian Andrzej Siewior
2021-12-14T14:03:24Z

Hi,

The following patches are from the PREEMPT_RT queue. One patch was
applied, one added so here are eight again. I can post them in smaller
batches if that is preferred.
It is mostly about disabling interrupts/preemption which leads to
problems. Unfortunately DRM_I915_LOW_LEVEL_TRACEPOINTS had to be
disabled because it acquires locks from within trace points. Making the
lock a raw_spinlock_t led to higher latencies during video playback
https://lore.kernel.org/all/20211006164628.s2mtsdd2jdbfyf7g@linutronix.de/

and I'm not sure if I hit the worse case here.
I tested it on a SandyBridge with built-in i915 by using X, OpenGL and
playing videos without noticing any warnings. However, some code paths
were not entered.

Sebastian