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drm/panfrost: Fix scheduler workqueue bug

PATCH In review Philipp Stanner 3 participants 3 messages Jul 9, 2025

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#0 lore raw

PATCH 1/1 drm/panfrost: Fix scheduler workqueue bug

When the GPU scheduler was ported to using a struct for its initialization parameters, it was overlooked that panfrost creates a distinct workqueue for timeout handling.

The pointer to this new workqueue is not initialized to the struct, resulting in NULL being passed to the scheduler, which then uses the system_wq for timeout handling.

Set the correct workqueue to the init args struct.

Fixes 796a9f55a8d1 ("drm/sched: Use struct for drm_sched_init() params")
---
 drivers/gpu/drm/panfrost/panfrost_job.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/gpu/drm/panfrost/panfrost_job.c +1 -1
index 5657106c2f7d..15e2d505550f 100644
@@ -841,7 +841,6 @@ int panfrost_job_init(struct panfrost_device *pfdev)
 		.num_rqs = DRM_SCHED_PRIORITY_COUNT,
 		.credit_limit = 2,
 		.timeout = msecs_to_jiffies(JOB_TIMEOUT_MS),
-		.timeout_wq = pfdev->reset.wq,
 		.name = "pan_js",
 		.dev = pfdev->dev,
 	};
@@ -879,6 +878,7 @@ int panfrost_job_init(struct panfrost_device *pfdev)
 	pfdev->reset.wq = alloc_ordered_workqueue("panfrost-reset", 0);
 	if (!pfdev->reset.wq)
 		return -ENOMEM;
+	args.timeout_wq = pfdev->reset.wq;
 
 	for (j = 0; j < NUM_JOB_SLOTS; j++) {
 		js->queue[j].fence_context = dma_fence_context_alloc(1);
Signature · 1 line
2.49.0
Reviewed-by on v1 1/1
#1 lore raw
Quoted 32 lines · Philipp Stanner

When the GPU scheduler was ported to using a struct for its initialization parameters, it was overlooked that panfrost creates a distinct workqueue for timeout handling.

The pointer to this new workqueue is not initialized to the struct, resulting in NULL being passed to the scheduler, which then uses the system_wq for timeout handling.

Set the correct workqueue to the init args struct.

Fixes 796a9f55a8d1 ("drm/sched: Use struct for drm_sched_init() params")
---
  drivers/gpu/drm/panfrost/panfrost_job.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)
drivers/gpu/drm/panfrost/panfrost_job.c +0 -1
index 5657106c2f7d..15e2d505550f 100644
@@ -841,7 +841,6 @@ int panfrost_job_init(struct panfrost_device *pfdev)
  		.num_rqs = DRM_SCHED_PRIORITY_COUNT,
  		.credit_limit = 2,
  		.timeout = msecs_to_jiffies(JOB_TIMEOUT_MS),
-		.timeout_wq = pfdev->reset.wq,
  		.name = "pan_js",
  		.dev = pfdev->dev,
  	};

drivers/gpu/drm/panfrost/panfrost_job.c int panfrost_job_init(struct panfrost_device *pfdev) · line 884

Quoted 7 lines
drivers/gpu/drm/panfrost/panfrost_job.c +1 -0
@@ -879,6 +878,7 @@ int panfrost_job_init(struct panfrost_device *pfdev)
  	pfdev->reset.wq = alloc_ordered_workqueue("panfrost-reset", 0);
  	if (!pfdev->reset.wq)
  		return -ENOMEM;
+	args.timeout_wq = pfdev->reset.wq;
 
  	for (j = 0; j < NUM_JOB_SLOTS; j++) {
  		js->queue[j].fence_context = dma_fence_context_alloc(1);

Regards,

Tvrtko

maintainer Reviewed-by on v1 1/1
#2 lore raw
In reply to Philipp Stanner
Quoted 8 lines · Philipp Stanner

When the GPU scheduler was ported to using a struct for its initialization parameters, it was overlooked that panfrost creates a distinct workqueue for timeout handling.

The pointer to this new workqueue is not initialized to the struct, resulting in NULL being passed to the scheduler, which then uses the system_wq for timeout handling.

Quoted 7 lines

Set the correct workqueue to the init args struct.

Fixes 796a9f55a8d1 ("drm/sched: Use struct for drm_sched_init() params")
Quoted 24 lines
---
 drivers/gpu/drm/panfrost/panfrost_job.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/gpu/drm/panfrost/panfrost_job.c +1 -1
index 5657106c2f7d..15e2d505550f 100644
@@ -841,7 +841,6 @@ int panfrost_job_init(struct panfrost_device *pfdev)
 		.num_rqs = DRM_SCHED_PRIORITY_COUNT,
 		.credit_limit = 2,
 		.timeout = msecs_to_jiffies(JOB_TIMEOUT_MS),
-		.timeout_wq = pfdev->reset.wq,
 		.name = "pan_js",
 		.dev = pfdev->dev,
 	};
@@ -879,6 +878,7 @@ int panfrost_job_init(struct panfrost_device *pfdev)
 	pfdev->reset.wq = alloc_ordered_workqueue("panfrost-reset", 0);
 	if (!pfdev->reset.wq)
 		return -ENOMEM;
+	args.timeout_wq = pfdev->reset.wq;
 
 	for (j = 0; j < NUM_JOB_SLOTS; j++) {
 		js->queue[j].fence_context = dma_fence_context_alloc(1);