drm/msm: Drop struct_mutex from the retire path

Now that we are not relying on dev->struct_mutex to protect the
ring->submits lists, drop the struct_mutex lock.
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Jordan Crouse <jcrouse@codeaurora.org>
Reviewed-by: Kristian H. Kristensen <hoegsberg@google.com>
Signed-off-by: Rob Clark <robdclark@chromium.org>

drivers/gpu/drm/msm/msm_gpu.c

@@ -713,7 +713,7 @@ static void retire_submit(struct msm_gpu *gpu, struct msm_ringbuffer *ring,
 
 		msm_gem_active_put(&msm_obj->base);
 		msm_gem_unpin_iova(&msm_obj->base, submit->aspace);
-		drm_gem_object_put_locked(&msm_obj->base);
+		drm_gem_object_put(&msm_obj->base);
 	}
 
 	pm_runtime_mark_last_busy(&gpu->pdev->dev);
@@ -728,11 +728,8 @@ static void retire_submit(struct msm_gpu *gpu, struct msm_ringbuffer *ring,
 
 static void retire_submits(struct msm_gpu *gpu)
 {
-	struct drm_device *dev = gpu->dev;
 	int i;
 
-	WARN_ON(!mutex_is_locked(&dev->struct_mutex));
-
 	/* Retire the commits starting with highest priority */
 	for (i = 0; i < gpu->nr_rings; i++) {
 		struct msm_ringbuffer *ring = gpu->rb[i];
@@ -762,15 +759,12 @@ static void retire_submits(struct msm_gpu *gpu)
 static void retire_worker(struct kthread_work *work)
 {
 	struct msm_gpu *gpu = container_of(work, struct msm_gpu, retire_work);
-	struct drm_device *dev = gpu->dev;
 	int i;
 
 	for (i = 0; i < gpu->nr_rings; i++)
 		update_fences(gpu, gpu->rb[i], gpu->rb[i]->memptrs->fence);
 
-	mutex_lock(&dev->struct_mutex);
 	retire_submits(gpu);
-	mutex_unlock(&dev->struct_mutex);
 }
 
 /* call from irq handler to schedule work to retire bo's */