drm: Add reference counting to drm_atomic_state
drm_atomic_state has a complicated single owner model that tracks the
single reference from allocation through to destruction on another
thread - or perhaps on a local error path. We can simplify this tracking
by using reference counting (at a cost of a few more atomics). This is
even more beneficial when the lifetime of the state becomes more
convoluted than being passed to a single worker thread for the commit.
v2: Double check !intel atomic_commit functions for missing gets
v3: Update kerneldocs
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Eric Engestrom <eric.engestrom@imgtec.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161014121833.439-27-chris@chris-wilson.co.uk
diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
index 5f48431..9f62228 100644
--- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
+++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
@@ -464,7 +464,7 @@
drm_atomic_helper_cleanup_planes(dev, old_state);
- drm_atomic_state_free(old_state);
+ drm_atomic_state_put(old_state);
/* Complete the commit, wake up any waiter. */
spin_lock(&dc->commit.wait.lock);
@@ -521,6 +521,7 @@
/* Swap the state, this is the point of no return. */
drm_atomic_helper_swap_state(state, true);
+ drm_atomic_state_get(state);
if (async)
queue_work(dc->wq, &commit->work);
else