diff mbox series

drm/i915/guc: Cancel GuC engine busyness worker synchronously

Message ID 20220726205116.3148847-1-umesh.nerlige.ramappa@intel.com (mailing list archive)
State New, archived
Headers show
Series drm/i915/guc: Cancel GuC engine busyness worker synchronously | expand

Commit Message

Umesh Nerlige Ramappa July 26, 2022, 8:51 p.m. UTC
The worker is canceled in gt_park path, but earlier it was assumed that
gt_park path cannot sleep and the cancel is asynchronous. This caused a
race with suspend flow where the worker runs after suspend and causes an
unclaimed register access warning. Cancel the worker synchronously since
the gt_park is indeed allowed to sleep.

Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Fixes: 77cdd054dd2c ("drm/i915/pmu: Connect engine busyness stats from GuC to pmu")
---
 drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

Comments

John Harrison July 28, 2022, 1:41 a.m. UTC | #1
On 7/26/2022 13:51, Nerlige Ramappa, Umesh wrote:
> The worker is canceled in gt_park path, but earlier it was assumed that
> gt_park path cannot sleep and the cancel is asynchronous. This caused a
> race with suspend flow where the worker runs after suspend and causes an
> unclaimed register access warning. Cancel the worker synchronously since
> the gt_park is indeed allowed to sleep.
>
> Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
> Fixes: 77cdd054dd2c ("drm/i915/pmu: Connect engine busyness stats from GuC to pmu")
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>

> ---
>   drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c | 7 ++++++-
>   1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> index 76916aed897a..0b7a5ecb640a 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> @@ -1438,7 +1438,12 @@ void intel_guc_busyness_park(struct intel_gt *gt)
>   	if (!guc_submission_initialized(guc))
>   		return;
>   
> -	cancel_delayed_work(&guc->timestamp.work);
> +	/*
> +	 * There is a race with suspend flow where the worker runs after suspend
> +	 * and causes an unclaimed register access warning. Cancel the worker
> +	 * synchronously here.
> +	 */
> +	cancel_delayed_work_sync(&guc->timestamp.work);
>   
>   	/*
>   	 * Before parking, we should sample engine busyness stats if we need to.
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
index 76916aed897a..0b7a5ecb640a 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
@@ -1438,7 +1438,12 @@  void intel_guc_busyness_park(struct intel_gt *gt)
 	if (!guc_submission_initialized(guc))
 		return;
 
-	cancel_delayed_work(&guc->timestamp.work);
+	/*
+	 * There is a race with suspend flow where the worker runs after suspend
+	 * and causes an unclaimed register access warning. Cancel the worker
+	 * synchronously here.
+	 */
+	cancel_delayed_work_sync(&guc->timestamp.work);
 
 	/*
 	 * Before parking, we should sample engine busyness stats if we need to.