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[v3,0/2] drm/msm/gpu: System suspend fixes

Message ID 20220108180913.814448-1-robdclark@gmail.com
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Series drm/msm/gpu: System suspend fixes | expand

Message

Rob Clark Jan. 8, 2022, 6:09 p.m. UTC 
From: Rob Clark <robdclark@chromium.org>

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(-)