virtio-gpu: fix output lookup

Needed for multihead setups where we can have disabled
outputs and therefore plane->crtc can be NULL.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

diff --git a/drivers/gpu/drm/virtio/virtgpu_plane.c b/drivers/gpu/drm/virtio/virtgpu_plane.c
index 70b44a2345ab43e2ac1bef8ded76c292ab752884..e50674bccb0929f34dce70c702bb839096ec9036 100644 (file)
--- a/drivers/gpu/drm/virtio/virtgpu_plane.c
+++ b/drivers/gpu/drm/virtio/virtgpu_plane.c
@@ -63,11 +63,17 @@ static void virtio_gpu_plane_atomic_update(struct drm_plane *plane,
 {
        struct drm_device *dev = plane->dev;
        struct virtio_gpu_device *vgdev = dev->dev_private;
-       struct virtio_gpu_output *output = drm_crtc_to_virtio_gpu_output(plane->crtc);
+       struct virtio_gpu_output *output = NULL;
        struct virtio_gpu_framebuffer *vgfb;
        struct virtio_gpu_object *bo;
        uint32_t handle;
 
+       if (plane->state->crtc)
+               output = drm_crtc_to_virtio_gpu_output(plane->state->crtc);
+       if (old_state->crtc)
+               output = drm_crtc_to_virtio_gpu_output(old_state->crtc);
+       WARN_ON(!output);
+
        if (plane->state->fb) {
                vgfb = to_virtio_gpu_framebuffer(plane->state->fb);
                bo = gem_to_virtio_gpu_obj(vgfb->obj);