drm: Clear the fence pointer when writeback job signaled

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>
Reviewed-by: Brian Starkey <brian.starkey@arm.com>
Reviewed-by: James Qian Wang (Arm Technology China) <james.qian.wang@arm.com>
Signed-off-by: james qian wang (Arm Technology China) <james.qian.wang@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1564571048-15029-3-git-send-email-lowry.li@arm.com

diff --git a/drivers/gpu/drm/drm_writeback.c b/drivers/gpu/drm/drm_writeback.c
index ff138b6..43d9e3b 100644 (file)
--- 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);
 }
 EXPORT_SYMBOL(drm_writeback_cleanup_job);
@@ -366,25 +369,29 @@ drm_writeback_signal_completion(struct drm_writeback_connector *wb_connector,
 {
        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);
-               }
-       }
+
        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;
+       }
+
        INIT_WORK(&job->cleanup_work, cleanup_work);
        queue_work(system_long_wq, &job->cleanup_work);
 }