drm/vc4: update cursors asynchronously through atomic

Add support for async updates of cursors by using the new atomic
interface for that. Basically what this commit does is do what
vc4_update_plane() did but through atomic.

v7: Place the drm_atomic_set_fb_for_plane() call after the new
    FB has been applied to the HW to avoid possible use-after-free
    issues
v6: add missing drm_atomic_set_fb_for_plane() in
    vc4_plane_atomic_async_update() (Boris Brezillon)
v5: add missing call to vc4_plane_atomic_check() (Eric Anholt)
v4: add drm_atomic_helper_async() commit (Eric Anholt)
v3: move size checks back to drivers (Ville Syrjälä)
v2: move fb setting to core and use new state (Eric Anholt)

Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180330085445.31726-1-boris.brezillon@bootlin.com

1 files changed, 20 insertions, 0 deletions

diff --git a/drivers/gpu/drm/vc4/vc4_kms.c b/drivers/gpu/drm/vc4/vc4_kms.c
index ba60153dddb5..e791e498a3dd 100644
--- a/drivers/gpu/drm/vc4/vc4_kms.c
+++ b/drivers/gpu/drm/vc4/vc4_kms.c
@@ -90,6 +90,26 @@ static int vc4_atomic_commit(struct drm_device *dev,
 	struct vc4_dev *vc4 = to_vc4_dev(dev);
 	int ret;
 
+	if (state->async_update) {
+		ret = down_interruptible(&vc4->async_modeset);
+		if (ret)
+			return ret;
+
+		ret = drm_atomic_helper_prepare_planes(dev, state);
+		if (ret) {
+			up(&vc4->async_modeset);
+			return ret;
+		}
+
+		drm_atomic_helper_async_commit(dev, state);
+
+		drm_atomic_helper_cleanup_planes(dev, state);
+
+		up(&vc4->async_modeset);
+
+		return 0;
+	}
+
 	ret = drm_atomic_helper_setup_commit(state, nonblock);
 	if (ret)
 		return ret;