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| author | Rob Clark <robdclark@chromium.org> | 2023-01-10 15:14:43 -0800 |
|---|---|---|
| committer | Rob Clark <robdclark@chromium.org> | 2023-01-16 10:40:24 -0800 |
| commit | fadcc3ab1302d4e5baa32c272b658221f0066696 (patch) | |
| tree | ebf4601780315361f34dca1d75c0385176fdadf9 /drivers/gpu/drm/msm/msm_gpu.h | |
| parent | 6563f60f14cbb3dcbdc4e1d8469fc0fbaaa80544 (diff) | |
| download | linux-stable-fadcc3ab1302d4e5baa32c272b658221f0066696.tar.gz linux-stable-fadcc3ab1302d4e5baa32c272b658221f0066696.tar.bz2 linux-stable-fadcc3ab1302d4e5baa32c272b658221f0066696.zip | |
drm/msm/gpu: Bypass PM QoS constraint for idle clamp
Change idle freq clamping back to the direct method, bypassing PM QoS
requests. The problem with using PM QoS requests is they call
(indirectly) the governors ->get_target_freq() which goes thru a
get_dev_status() cycle. The problem comes when the GPU becomes active
again and we remove the idle-clamp request, we go through another
get_dev_status() cycle for the period that the GPU has been idle, which
triggers the governor to lower the target freq excessively.
This partially reverts commit 7c0ffcd40b16 ("drm/msm/gpu: Respect PM QoS
constraints"), but preserves the use of boost QoS request, so that it
will continue to play nicely with other QoS requests such as a cooling
device. This also mostly undoes commit 78f815c1cf8f ("drm/msm: return the
average load over the polling period")
Signed-off-by: Rob Clark <robdclark@chromium.org>
Patchwork: https://patchwork.freedesktop.org/patch/517785/
Link: https://lore.kernel.org/r/20230110231447.1939101-3-robdclark@gmail.com
Reviewed-by: Chia-I Wu <olvaffe@gmail.com>
Diffstat (limited to 'drivers/gpu/drm/msm/msm_gpu.h')
| -rw-r--r-- | drivers/gpu/drm/msm/msm_gpu.h | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/drivers/gpu/drm/msm/msm_gpu.h b/drivers/gpu/drm/msm/msm_gpu.h index 9e36f6c9bc29..a771f56ed70f 100644 --- a/drivers/gpu/drm/msm/msm_gpu.h +++ b/drivers/gpu/drm/msm/msm_gpu.h @@ -109,11 +109,15 @@ struct msm_gpu_devfreq { struct mutex lock; /** - * idle_constraint: + * idle_freq: * - * A PM QoS constraint to limit max freq while the GPU is idle. + * Shadow frequency used while the GPU is idle. From the PoV of + * the devfreq governor, we are continuing to sample busyness and + * adjust frequency while the GPU is idle, but we use this shadow + * value as the GPU is actually clamped to minimum frequency while + * it is inactive. */ - struct dev_pm_qos_request idle_freq; + unsigned long idle_freq; /** * boost_constraint: @@ -135,8 +139,6 @@ struct msm_gpu_devfreq { /** idle_time: Time of last transition to idle: */ ktime_t idle_time; - struct devfreq_dev_status average_status; - /** * idle_work: * |