[PATCH] drm/panfrost: Don't corrupt the queue mutex on open/close

[PATCH] drm/panfrost: Don't corrupt the queue mutex on open/close

[Steven Price]

The mutex within the panfrost_queue_state should have the lifetime of
the queue, however it was erroneously initialised/destroyed during
panfrost_job_{open,close} which is called every time a client
opens/closes the drm node.

Move the initialisation/destruction to panfrost_job_{init,fini} where it
belongs.

Fixes: 1a11a88cfd9a ("drm/panfrost: Fix job timeout handling")
Signed-off-by: Steven Price <steven.price@arm.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
---
 drivers/gpu/drm/panfrost/panfrost_job.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c
index cfb431624eea..145ad37eda6a 100644
--- a/drivers/gpu/drm/panfrost/panfrost_job.c
+++ b/drivers/gpu/drm/panfrost/panfrost_job.c
@@ -595,6 +595,8 @@ int panfrost_job_init(struct panfrost_device *pfdev)
 	}
 
 	for (j = 0; j < NUM_JOB_SLOTS; j++) {
+		mutex_init(&js->queue[j].lock);
+
 		js->queue[j].fence_context = dma_fence_context_alloc(1);
 
 		ret = drm_sched_init(&js->queue[j].sched,
@@ -625,8 +627,10 @@ void panfrost_job_fini(struct panfrost_device *pfdev)
 
 	job_write(pfdev, JOB_INT_MASK, 0);
 
-	for (j = 0; j < NUM_JOB_SLOTS; j++)
+	for (j = 0; j < NUM_JOB_SLOTS; j++) {
 		drm_sched_fini(&js->queue[j].sched);
+		mutex_destroy(&js->queue[j].lock);
+	}
 
 }
 
@@ -638,7 +642,6 @@ int panfrost_job_open(struct panfrost_file_priv *panfrost_priv)
 	int ret, i;
 
 	for (i = 0; i < NUM_JOB_SLOTS; i++) {
-		mutex_init(&js->queue[i].lock);
 		sched = &js->queue[i].sched;
 		ret = drm_sched_entity_init(&panfrost_priv->sched_entity[i],
 					    DRM_SCHED_PRIORITY_NORMAL, &sched,
@@ -657,7 +660,6 @@ void panfrost_job_close(struct panfrost_file_priv *panfrost_priv)
 
 	for (i = 0; i < NUM_JOB_SLOTS; i++) {
 		drm_sched_entity_destroy(&panfrost_priv->sched_entity[i]);
-		mutex_destroy(&js->queue[i].lock);
 		/* Ensure any timeouts relating to this client have completed */
 		flush_delayed_work(&js->queue[i].sched.work_tdr);
 	}
-- 
2.20.1

Re: [PATCH] drm/panfrost: Don't corrupt the queue mutex on open/close

[Boris Brezillon]

On Thu, 29 Oct 2020 17:00:47 +0000
Steven Price <steven.price@arm.com> wrote:

> The mutex within the panfrost_queue_state should have the lifetime of
> the queue, however it was erroneously initialised/destroyed during
> panfrost_job_{open,close} which is called every time a client
> opens/closes the drm node.
> 
> Move the initialisation/destruction to panfrost_job_{init,fini} where it
> belongs.
> 

Queued to drm-misc-next.

Thanks,

Boris

> Fixes: 1a11a88cfd9a ("drm/panfrost: Fix job timeout handling")
> Signed-off-by: Steven Price <steven.price@arm.com>
> Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
> ---
>  drivers/gpu/drm/panfrost/panfrost_job.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c
> index cfb431624eea..145ad37eda6a 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_job.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_job.c
> @@ -595,6 +595,8 @@ int panfrost_job_init(struct panfrost_device *pfdev)
>  	}
>  
>  	for (j = 0; j < NUM_JOB_SLOTS; j++) {
> +		mutex_init(&js->queue[j].lock);
> +
>  		js->queue[j].fence_context = dma_fence_context_alloc(1);
>  
>  		ret = drm_sched_init(&js->queue[j].sched,
> @@ -625,8 +627,10 @@ void panfrost_job_fini(struct panfrost_device *pfdev)
>  
>  	job_write(pfdev, JOB_INT_MASK, 0);
>  
> -	for (j = 0; j < NUM_JOB_SLOTS; j++)
> +	for (j = 0; j < NUM_JOB_SLOTS; j++) {
>  		drm_sched_fini(&js->queue[j].sched);
> +		mutex_destroy(&js->queue[j].lock);
> +	}
>  
>  }
>  
> @@ -638,7 +642,6 @@ int panfrost_job_open(struct panfrost_file_priv *panfrost_priv)
>  	int ret, i;
>  
>  	for (i = 0; i < NUM_JOB_SLOTS; i++) {
> -		mutex_init(&js->queue[i].lock);
>  		sched = &js->queue[i].sched;
>  		ret = drm_sched_entity_init(&panfrost_priv->sched_entity[i],
>  					    DRM_SCHED_PRIORITY_NORMAL, &sched,
> @@ -657,7 +660,6 @@ void panfrost_job_close(struct panfrost_file_priv *panfrost_priv)
>  
>  	for (i = 0; i < NUM_JOB_SLOTS; i++) {
>  		drm_sched_entity_destroy(&panfrost_priv->sched_entity[i]);
> -		mutex_destroy(&js->queue[i].lock);
>  		/* Ensure any timeouts relating to this client have completed */
>  		flush_delayed_work(&js->queue[i].sched.work_tdr);
>  	}