[PATCH] drm/atomic: Call ww_acquire_done after check phase is complete

Daniel Vetter daniel.vetter at ffwll.ch
Thu Aug 6 06:06:40 PDT 2015

We want to make sure that no one tries to acquire more locks and
states, and ww mutexes provide debug facilities for that. So use them.

v2: Only call acquire_done when ->atomic_check was successful to avoid
falling over an -EDEADLK (spotted by Maarten).

Cc: Rob Clark <robdclark at gmail.com>
Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
 drivers/gpu/drm/drm_atomic.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 422183e7ee7d..750ee96097b9 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -1268,6 +1268,9 @@ int drm_atomic_check_only(struct drm_atomic_state *state)
+	if (ret == 0)
+		ww_acquire_done(&state->acquire_ctx->ww_ctx);
 	return ret;

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