[PATCH v2 0/2] drm/msm/gpu: System suspend fixes

From: Rob Clark
Date: Sat Jan 08 2022 - 12:43:05 EST


From: Rob Clark <robdclark@xxxxxxxxxxxx>

Because system suspend uses pm_runtime_force_suspend() we can't rely
runpm refcnt's to protect us if the GPU is active, etc. Fortunately
*usually* the GPU is idle when system suspend is triggered. But that
isn't quite good enough.

The first patch attempts to block for a modest amount of time until GPU
is idle (and failing that, returns -EBUSY). We could have taken a
slightly easier approach and just returned -EBUSY if GPU is not idle,
but that would cause system suspend to fail. And no one likes pulling
a hot laptop out of their backpack.

The second patch avoids getting devfreq callbacks after suspend, since
pm_runtime_force_suspend() breaks the pm_runtime_get_if_in_use() tricks
used to deal with devfreq callbacks while suspended.

Rob Clark (2):
drm/msm/gpu: Wait for idle before suspending
drm/msm/gpu: Cancel idle/boost work on suspend

drivers/gpu/drm/msm/adreno/adreno_device.c | 18 ++++++++++++++++++
drivers/gpu/drm/msm/msm_gpu.c | 3 +++
drivers/gpu/drm/msm/msm_gpu.h | 3 +++
drivers/gpu/drm/msm/msm_gpu_devfreq.c | 21 +++++++++++++++++++--
4 files changed, 43 insertions(+), 2 deletions(-)

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2.33.1