drm/vc4: Use the atomic state's commit workqueue.

Now that we're using the atomic helpers for fence waits, we can use
the same codepath as drm_atomic_helper_commit() does for async,
getting rid of our custom vc4_commit struct.

Signed-off-by: Eric Anholt <eric@anholt.net>
Link: http://patchwork.freedesktop.org/patch/msgid/20170621185002.28563-3-eric@anholt.net
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>

drivers/gpu/drm/vc4/vc4_kms.c

@@ -29,16 +29,9 @@ static void vc4_output_poll_changed(struct drm_device *dev)
 	drm_fbdev_cma_hotplug_event(vc4->fbdev);
 }
 
-struct vc4_commit {
-	struct drm_device *dev;
-	struct drm_atomic_state *state;
-	struct vc4_seqno_cb cb;
-};
-
 static void
-vc4_atomic_complete_commit(struct vc4_commit *c)
+vc4_atomic_complete_commit(struct drm_atomic_state *state)
 {
-	struct drm_atomic_state *state = c->state;
 	struct drm_device *dev = state->dev;
 	struct vc4_dev *vc4 = to_vc4_dev(dev);
 
@@ -72,28 +65,14 @@ vc4_atomic_complete_commit(struct vc4_commit *c)
 	drm_atomic_state_put(state);
 
 	up(&vc4->async_modeset);
-
-	kfree(c);
-}
-
-static void
-vc4_atomic_complete_commit_seqno_cb(struct vc4_seqno_cb *cb)
-{
-	struct vc4_commit *c = container_of(cb, struct vc4_commit, cb);
-
-	vc4_atomic_complete_commit(c);
 }
 
-static struct vc4_commit *commit_init(struct drm_atomic_state *state)
+static void commit_work(struct work_struct *work)
 {
-	struct vc4_commit *c = kzalloc(sizeof(*c), GFP_KERNEL);
-
-	if (!c)
-		return NULL;
-	c->dev = state->dev;
-	c->state = state;
-
-	return c;
+	struct drm_atomic_state *state = container_of(work,
+						      struct drm_atomic_state,
+						      commit_work);
+	vc4_atomic_complete_commit(state);
 }
 
 /**
@@ -115,29 +94,19 @@ static int vc4_atomic_commit(struct drm_device *dev,
 {
 	struct vc4_dev *vc4 = to_vc4_dev(dev);
 	int ret;
-	int i;
-	uint64_t wait_seqno = 0;
-	struct vc4_commit *c;
-	struct drm_plane *plane;
-	struct drm_plane_state *new_state;
-
-	c = commit_init(state);
-	if (!c)
-		return -ENOMEM;
 
 	ret = drm_atomic_helper_setup_commit(state, nonblock);
 	if (ret)
 		return ret;
 
+	INIT_WORK(&state->commit_work, commit_work);
+
 	ret = down_interruptible(&vc4->async_modeset);
-	if (ret) {
-		kfree(c);
+	if (ret)
 		return ret;
-	}
 
 	ret = drm_atomic_helper_prepare_planes(dev, state);
 	if (ret) {
-		kfree(c);
 		up(&vc4->async_modeset);
 		return ret;
 	}
@@ -146,22 +115,11 @@ static int vc4_atomic_commit(struct drm_device *dev,
 		ret = drm_atomic_helper_wait_for_fences(dev, state, true);
 		if (ret) {
 			drm_atomic_helper_cleanup_planes(dev, state);
-			kfree(c);
 			up(&vc4->async_modeset);
 			return ret;
 		}
 	}
 
-	for_each_plane_in_state(state, plane, new_state, i) {
-		if ((plane->state->fb != new_state->fb) && new_state->fb) {
-			struct drm_gem_cma_object *cma_bo =
-				drm_fb_cma_get_gem_obj(new_state->fb, 0);
-			struct vc4_bo *bo = to_vc4_bo(&cma_bo->base);
-
-			wait_seqno = max(bo->seqno, wait_seqno);
-		}
-	}
-
 	/*
 	 * This is the point of no return - everything below never fails except
 	 * when the hw goes bonghits. Which means we can commit the new state on
@@ -187,13 +145,10 @@ static int vc4_atomic_commit(struct drm_device *dev,
 	 */
 
 	drm_atomic_state_get(state);
-	if (nonblock) {
-		vc4_queue_seqno_cb(dev, &c->cb, wait_seqno,
-				   vc4_atomic_complete_commit_seqno_cb);
-	} else {
-		vc4_wait_for_seqno(dev, wait_seqno, ~0ull, false);
-		vc4_atomic_complete_commit(c);
-	}
+	if (nonblock)
+		queue_work(system_unbound_wq, &state->commit_work);
+	else
+		vc4_atomic_complete_commit(state);
 
 	return 0;
 }