[RFC PATCH 6/6] drm/nouveau: Remove hacky fence check

[Philipp Stanner <phasta@kernel.org>]

nouveau_cli_work() contains a section where a dma_fence lock is manually
taken and immediately released afterwards. This was added in

	commit c8a5d5ea3ba6 ("nouveau: fix client work fence deletion race")

as a bugfix because the function dma_fence_is_signaled() could return
true while the fence was still signaling.

The fix was later modified in

	commit a80d12eafad1 ("drm/nouveau: Simplify nouveau_cli_work")

Luckily, the dma_fence backend now fully synchronizes
dma_fence_is_signaled() with the spinlock. Thus, the check in nouveau is
not necessary anymore.

Remove the manual lock-unlock section.

Signed-off-by: Philipp Stanner <phasta@kernel.org>
---
 drivers/gpu/drm/nouveau/nouveau_drm.c | 13 -------------
 1 file changed, 13 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_drm.c b/drivers/gpu/drm/nouveau/nouveau_drm.c
index b0f9fb10a74d..74632bb29f2f 100644
--- a/drivers/gpu/drm/nouveau/nouveau_drm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_drm.c
@@ -163,19 +163,6 @@ nouveau_cli_work(struct work_struct *w)
 		struct dma_fence *fence = work->fence;
 
 		if (!fence || dma_fence_is_signaled(fence)) {
-			if (fence) {
-				unsigned long flags;
-
-				/*
-				 * Because fence can still be in the process of
-				 * processing the callback list, and the
-				 * callback references the work we are about to
-				 * free, we need to sync with the callback
-				 * processing before freeing the work.
-				 */
-				dma_fence_lock_irqsave(fence, flags);
-				dma_fence_unlock_irqrestore(fence, flags);
-			}
 			list_del(&work->head);
 			work->func(work);
 			dma_fence_put(fence);
-- 
2.56.0