On Thu, Aug 01, 2019 at 06:31:13AM +0000, Lowry Li (Arm Technology China) wrote:

Hi Liviu,

On Wed, Jul 31, 2019 at 01:15:25PM +0000, Liviu Dudau wrote:

...

Hi Lowry,

On Wed, Jul 31, 2019 at 11:04:45AM +0000, Lowry Li (Arm Technology China) wrote:

...

During it signals the completion of a writeback job, after releasing the out_fence, we'd clear the pointer.

Check if fence left over in drm_writeback_cleanup_job(), release it.

Signed-off-by: Lowry Li (Arm Technology China) lowry.li@arm.com

drivers/gpu/drm/drm_writeback.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/drm_writeback.c b/drivers/gpu/drm/drm_writeback.c index ff138b6..43d9e3b 100644 --- a/drivers/gpu/drm/drm_writeback.c +++ b/drivers/gpu/drm/drm_writeback.c @@ -324,6 +324,9 @@ void drm_writeback_cleanup_job(struct drm_writeback_job *job) if (job->fb) drm_framebuffer_put(job->fb);

• if (job->out_fence)

• dma_fence_put(job->out_fence);
  

• kfree(job);

}

This change looks good.

...

EXPORT_SYMBOL(drm_writeback_cleanup_job); @@ -366,25 +369,29 @@ static void cleanup_work(struct work_struct *work) { unsigned long flags; struct drm_writeback_job *job;

• struct dma_fence *out_fence;

  spin_lock_irqsave(&wb_connector->job_lock, flags); job = list_first_entry_or_null(&wb_connector->job_queue, struct drm_writeback_job, list_entry);

• if (job) {

• if (job) list_del(&job->list_entry);

• if (job->out_fence) {
  

• 	if (status)
  

• 		dma_fence_set_error(job->out_fence, status);
  

• 	dma_fence_signal(job->out_fence);
  

• 	dma_fence_put(job->out_fence);
  

*Here*

...

• }
  

• }

• spin_unlock_irqrestore(&wb_connector->job_lock, flags);

  if (WARN_ON(!job)) return;

• out_fence = job->out_fence;

• if (out_fence) {

• if (status)
  

• 	dma_fence_set_error(out_fence, status);
  

• dma_fence_signal(out_fence);
  

• dma_fence_put(out_fence);
  

• job->out_fence = NULL;
  

• }

I don't get the point of this change. Why not just add job->out_fence = NULL where *Here* is?

Best regards, Liviu

Besides setting NULL, also did a refine by moving the fence operation out of the lock block.

OK, now it makes sense. May I suggest you add that to the commit message?

Otherwise, Acked-by: Liviu Dudau liviu.dudau@arm.com

Best regards, Liviu

Best regards, Lowry

...

...

INIT_WORK(&job->cleanup_work, cleanup_work); queue_work(system_long_wq, &job->cleanup_work); } -- 1.9.1

--

| I would like to | | fix the world, | | but they're not | | giving me the | \ source code! /

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¯\_(ツ)_/¯

-- Regards, Lowry