Re: [PATCH] drm/bridge/synopsys: dsi: Don't blindly call post_disable

[Laurent Pinchart]

Hi Matt,

Thank you for the patch.

On Wed, Apr 24, 2019 at 02:22:00PM +0000, Matt Redfearn wrote:
> The DRM documentation states that post_disable is an optional callback.
> As such an implementing device may not populate it. To avoid panicing
> the kernel by calling a NULL function pointer, we should NULL check it
> before blindy calling it.
> 
> Signed-off-by: Matt Redfearn <matt.redfearn@xxxxxxxxxx>

Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>

> ---
> 
>  drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> index 38e88071363..0ee440216b8 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> @@ -805,7 +805,8 @@ static void dw_mipi_dsi_bridge_post_disable(struct drm_bridge *bridge)
>  	 * This needs to be fixed in the drm_bridge framework and the API
>  	 * needs to be updated to manage our own call chains...
>  	 */
> -	dsi->panel_bridge->funcs->post_disable(dsi->panel_bridge);
> +	if (dsi->panel_bridge->funcs->post_disable)
> +		dsi->panel_bridge->funcs->post_disable(dsi->panel_bridge);
>  
>  	if (dsi->slave) {
>  		dw_mipi_dsi_disable(dsi->slave);

-- 
Regards,

Laurent Pinchart