[Intel-gfx] [PATCH] drm/atomic-helper: Simplify commit tracking locking

[Daniel Vetter]

The crtc->commit_lock only protects commit_list and commit_entry. If
we chase the pointer from the drm_atomic_state update structure, then
we don't need any locks (since we hold a reference already).

Simplify the locking accordingly.

Noticed while reviewing a patch from Boris.

Cc: Boris Brezillon <boris.brezillon at free-electrons.com>
Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
---
 drivers/gpu/drm/drm_atomic_helper.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 86d3093c6c9b..9bf86eb87fe1 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -1680,9 +1680,7 @@ void drm_atomic_helper_commit_hw_done(struct drm_atomic_state *old_state)
 
 		/* backend must have consumed any event by now */
 		WARN_ON(new_crtc_state->event);
-		spin_lock(&crtc->commit_lock);
 		complete_all(&commit->hw_done);
-		spin_unlock(&crtc->commit_lock);
 	}
 }
 EXPORT_SYMBOL(drm_atomic_helper_commit_hw_done);
@@ -1711,7 +1709,6 @@ void drm_atomic_helper_commit_cleanup_done(struct drm_atomic_state *old_state)
 		if (WARN_ON(!commit))
 			continue;
 
-		spin_lock(&crtc->commit_lock);
 		complete_all(&commit->cleanup_done);
 		WARN_ON(!try_wait_for_completion(&commit->hw_done));
 
@@ -1721,8 +1718,6 @@ void drm_atomic_helper_commit_cleanup_done(struct drm_atomic_state *old_state)
 		if (try_wait_for_completion(&commit->flip_done))
 			goto del_commit;
 
-		spin_unlock(&crtc->commit_lock);
-
 		/* We must wait for the vblank event to signal our completion
 		 * before releasing our reference, since the vblank work does
 		 * not hold a reference of its own. */
@@ -1732,8 +1727,8 @@ void drm_atomic_helper_commit_cleanup_done(struct drm_atomic_state *old_state)
 			DRM_ERROR("[CRTC:%d:%s] flip_done timed out\n",
 				  crtc->base.id, crtc->name);
 
-		spin_lock(&crtc->commit_lock);
 del_commit:
+		spin_lock(&crtc->commit_lock);
 		list_del(&commit->commit_entry);
 		spin_unlock(&crtc->commit_lock);
 	}
-- 
2.11.0