On Tue, 24 Jul 2018 15:32:15 +0200
Boris Brezillon <boris.brezillon@xxxxxxxxxxx> wrote:
> Async plane update is supposed to work only when updating the FB or FB
> position of an already enabled plane. That does not apply to requests
> where the plane was previously disabled or assigned to a different
> CTRC.
>
> Check old_plane_state->crtc value to make sure async plane update is
> allowed.
>
> Fixes: fef9df8b5945 ("drm/atomic: initial support for asynchronous plane update")
> Cc: <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxx>
> Reviewed-by: Eric Anholt <eric@xxxxxxxxxx>
Applied to drm-misc-fixes.
> ---
> Changes in v2:
> - Cc stable
> - Add Eric's R-b
> ---
> drivers/gpu/drm/drm_atomic_helper.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
> index 866a2cc72ef6..f7ccfebd3ca8 100644
> --- a/drivers/gpu/drm/drm_atomic_helper.c
> +++ b/drivers/gpu/drm/drm_atomic_helper.c
> @@ -1555,7 +1555,8 @@ int drm_atomic_helper_async_check(struct drm_device *dev,
> if (n_planes != 1)
> return -EINVAL;
>
> - if (!new_plane_state->crtc)
> + if (!new_plane_state->crtc ||
> + old_plane_state->crtc != new_plane_state->crtc)
> return -EINVAL;
>
> funcs = plane->helper_private;
