[PATCH] drm/virtio: add plane check

[Gerd Hoffmann]

Use drm_atomic_helper_check_plane_state()
to sanity check the plane state.

Signed-off-by: Gerd Hoffmann <kraxel@xxxxxxxxxx>
---
 drivers/gpu/drm/virtio/virtgpu_plane.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_plane.c b/drivers/gpu/drm/virtio/virtgpu_plane.c
index 024c2aa0c929..3b377bb5b5cb 100644
--- a/drivers/gpu/drm/virtio/virtgpu_plane.c
+++ b/drivers/gpu/drm/virtio/virtgpu_plane.c
@@ -82,7 +82,22 @@ static const struct drm_plane_funcs virtio_gpu_plane_funcs = {
 static int virtio_gpu_plane_atomic_check(struct drm_plane *plane,
 					 struct drm_plane_state *state)
 {
-	return 0;
+	bool is_cursor = plane->type == DRM_PLANE_TYPE_CURSOR;
+	struct drm_crtc_state *crtc_state;
+	int ret;
+
+	if (!state->fb | !state->crtc)
+		return 0;
+
+	crtc_state = drm_atomic_get_crtc_state(state->state, state->crtc);
+	if (IS_ERR(crtc_state))
+                return PTR_ERR(crtc_state);
+
+	ret = drm_atomic_helper_check_plane_state(state, crtc_state,
+						  DRM_PLANE_HELPER_NO_SCALING,
+						  DRM_PLANE_HELPER_NO_SCALING,
+						  is_cursor, true);
+	return ret;
 }
 
 static void virtio_gpu_primary_plane_update(struct drm_plane *plane,
-- 
2.18.1