Re: [Freedreno] [PATCH] drm/msm: Fix return type of mdp4_lvds_connector_mode_valid

[Abhinav Kumar <quic_abhinavk@quicinc.com>]

Hi Nathan

Thanks for the patch.

On 9/13/2022 1:55 PM, Nathan Huckleberry wrote:
> The mode_valid field in drm_connector_helper_funcs is expected to be of
> type:
> enum drm_mode_status (* mode_valid) (struct drm_connector *connector,
>                                       struct drm_display_mode *mode);
> 
> The mismatched return type breaks forward edge kCFI since the underlying
> function definition does not match the function hook definition.
> 
> The return type of mdp4_lvds_connector_mode_valid should be changed from
> int to enum drm_mode_status.
> 
> Reported-by: Dan Carpenter <error27@gmail.com>
> Link: https://github.com/ClangBuiltLinux/linux/issues/1703
> Cc: llvm@lists.linux.dev
> Signed-off-by: Nathan Huckleberry <nhuck@google.com>

 From what I can see this one has been this way since lvds support was 
added. Hence this should have

Fixes: 3e87599b68e7 ("drm/msm/mdp4: add LVDS panel support")

Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
> ---
>   drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c | 5 +++--
>   1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c b/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c
> index 7288041dd86a..7444b75c4215 100644
> --- a/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c
> +++ b/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c
> @@ -56,8 +56,9 @@ static int mdp4_lvds_connector_get_modes(struct drm_connector *connector)
>   	return ret;
>   }
>   
> -static int mdp4_lvds_connector_mode_valid(struct drm_connector *connector,
> -				 struct drm_display_mode *mode)
> +static enum drm_mode_status
> +mdp4_lvds_connector_mode_valid(struct drm_connector *connector,
> +			       struct drm_display_mode *mode)
>   {
>   	struct mdp4_lvds_connector *mdp4_lvds_connector =
>   			to_mdp4_lvds_connector(connector);