Re: [PATCH 2/8] drm/sun4i: backend: Allow a NULL plane pointer to retrieve the format

[Neil Armstrong <narmstrong@baylibre.com>]

On 13/12/2017 16:33, Maxime Ripard wrote:
> The function converting the DRM format to its equivalent in the backend
> registers was assuming that we were having a plane.
> 
> However, we might want to use that function when setting up a plane using
> the frontend, in which case we will not have a plane associated to the
> backend's layer. Yet, we still need to setup the format to the one output
> by the frontend.
> 
> Test for NULL plane pointers before referencing them, so that we can work
> around it.
> 
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> ---
>  drivers/gpu/drm/sun4i/sun4i_backend.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/sun4i/sun4i_backend.c b/drivers/gpu/drm/sun4i/sun4i_backend.c
> index c99d1a7e815a..f971d3fb5ee4 100644
> --- a/drivers/gpu/drm/sun4i/sun4i_backend.c
> +++ b/drivers/gpu/drm/sun4i/sun4i_backend.c
> @@ -93,7 +93,7 @@ void sun4i_backend_layer_enable(struct sun4i_backend *backend,
>  static int sun4i_backend_drm_format_to_layer(struct drm_plane *plane,
>  					     u32 format, u32 *mode)
>  {
> -	if ((plane->type == DRM_PLANE_TYPE_PRIMARY) &&
> +	if (plane && (plane->type == DRM_PLANE_TYPE_PRIMARY) &&
>  	    (format == DRM_FORMAT_ARGB8888))
>  		format = DRM_FORMAT_XRGB8888;
>  
> 

Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>