On Thu 06 Jan 10:14 PST 2022, Rob Clark wrote:
> From: Rob Clark <robdclark@xxxxxxxxxxxx>
>
> 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.
>
Reviewed-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
Regards,
Bjorn
> Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
> ---
> drivers/gpu/drm/msm/adreno/adreno_device.c | 9 +++++++++
> drivers/gpu/drm/msm/msm_gpu.c | 3 +++
> drivers/gpu/drm/msm/msm_gpu.h | 3 +++
> 3 files changed, 15 insertions(+)
>
> diff --git a/drivers/gpu/drm/msm/adreno/adreno_device.c b/drivers/gpu/drm/msm/adreno/adreno_device.c
> index 93005839b5da..b677ca3fd75e 100644
> --- a/drivers/gpu/drm/msm/adreno/adreno_device.c
> +++ b/drivers/gpu/drm/msm/adreno/adreno_device.c
> @@ -611,6 +611,15 @@ static int adreno_resume(struct device *dev)
> static int adreno_suspend(struct device *dev)
> {
> struct msm_gpu *gpu = dev_to_gpu(dev);
> + int ret = 0;
> +
> + ret = wait_event_timeout(gpu->retire_event,
> + !msm_gpu_active(gpu),
> + msecs_to_jiffies(1000));
> + if (ret == 0) {
> + dev_err(dev, "Timeout waiting for GPU to suspend\n");
> + return -EBUSY;
> + }
>
> return gpu->funcs->pm_suspend(gpu);
> }
> diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
> index 0f78c2615272..2c1049c0ea14 100644
> --- a/drivers/gpu/drm/msm/msm_gpu.c
> +++ b/drivers/gpu/drm/msm/msm_gpu.c
> @@ -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);
> diff --git a/drivers/gpu/drm/msm/msm_gpu.h b/drivers/gpu/drm/msm/msm_gpu.h
> index 445c6bfd4b6b..92aa1e9196c6 100644
> --- a/drivers/gpu/drm/msm/msm_gpu.h
> +++ b/drivers/gpu/drm/msm/msm_gpu.h
> @@ -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;
>
> --
> 2.33.1
>
