Commit 167a668a authored by Rob Clark's avatar Rob Clark
Browse files

drm/msm/gpu: Wait for idle before suspending 



System suspend uses pm_runtime_force_suspend(), which cheekily bypasses
the runpm reference counts.  This doesn't actually work so well when the
GPU is active.  So add a reasonable delay waiting for the GPU to become
idle.

Alternatively we could just return -EBUSY in this case, but that has the
disadvantage of causing system suspend to fail.

v2: s/ret/remaining [sboyd], and switch to using active_submits count
    to ensure we aren't racing with submit cleanup (and devfreq idle
    work getting scheduled, etc)
v3: fix inverted logic

Signed-off-by: default avatarRob Clark <robdclark@chromium.org>
Reviewed-by: default avatarBjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: default avatarAngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20220108180913.814448-2-robdclark@gmail.com


Signed-off-by: default avatarRob Clark <robdclark@chromium.org>
parent 5e761a22

drivers/gpu/drm/msm/adreno/adreno_device.c

+18 −0
Original line number Diff line number Diff line
@@ -608,9 +608,27 @@ static int adreno_resume(struct device *dev) 
	return gpu->funcs->pm_resume(gpu);

}



static int active_submits(struct msm_gpu *gpu)

{

	int active_submits;

	mutex_lock(&gpu->active_lock);

	active_submits = gpu->active_submits;

	mutex_unlock(&gpu->active_lock);

	return active_submits;

}



static int adreno_suspend(struct device *dev)

{

	struct msm_gpu *gpu = dev_to_gpu(dev);

	int remaining;



	remaining = wait_event_timeout(gpu->retire_event,

				       active_submits(gpu) == 0,

				       msecs_to_jiffies(1000));

	if (remaining == 0) {

		dev_err(dev, "Timeout waiting for GPU to suspend\n");

		return -EBUSY;

	}



	return gpu->funcs->pm_suspend(gpu);

}

drivers/gpu/drm/msm/msm_gpu.c

+3 −0
Original line number Diff line number Diff line
@@ -703,6 +703,8 @@ static void retire_submits(struct msm_gpu *gpu) 
			}

		}

	}



	wake_up_all(&gpu->retire_event);

}



static void retire_worker(struct kthread_work *work)
@@ -848,6 +850,7 @@ int msm_gpu_init(struct drm_device *drm, struct platform_device *pdev, 
	INIT_LIST_HEAD(&gpu->active_list);

	mutex_init(&gpu->active_lock);

	mutex_init(&gpu->lock);

	init_waitqueue_head(&gpu->retire_event);

	kthread_init_work(&gpu->retire_work, retire_worker);

	kthread_init_work(&gpu->recover_work, recover_worker);

	kthread_init_work(&gpu->fault_work, fault_worker);

drivers/gpu/drm/msm/msm_gpu.h

+3 −0
Original line number Diff line number Diff line
@@ -230,6 +230,9 @@ struct msm_gpu { 
	/* work for handling GPU recovery: */

	struct kthread_work recover_work;



	/** retire_event: notified when submits are retired: */

	wait_queue_head_t retire_event;



	/* work for handling active-list retiring: */

	struct kthread_work retire_work;