Re: [PATCH] drm/amd/display: fix NULL dereference

[Hamza Mahfooz]

On 11/14/23 01:36, José Pekkarinen wrote:
> The following patch will fix a minor issue where a debug message is
> referencing an struct that has just being checked whether is null or
> not. This has been noticed by using coccinelle, in the following output:
>
> drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c:540:25-29: ERROR: aconnector is NULL but dereferenced.
>
> Fixes: 5d72e247e58c9 ("drm/amd/display: switch DC over to the new DRM logging macros")
> Signed-off-by: José Pekkarinen <jose.pekkarinen@xxxxxxxxxxx>
> ---
>   drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c | 3 +--
>   1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
> index ed784cf27d39..7048dab5e356 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
> @@ -537,8 +537,7 @@ bool dm_helpers_dp_read_dpcd(
>   	struct amdgpu_dm_connector *aconnector = link->priv;
>   
>   	if (!aconnector) {
> -		drm_dbg_dp(aconnector->base.dev,
> -			   "Failed to find connector for link!\n");
> +		DRM_ERROR("Failed to find connector for link!");

I would prefer a patch that drops this error message entirely since
it's not particularly useful. As, it's only possible before hw init
(and at that point it's expected).

>   		return false;
>   	}
>   
--
Hamza