Re: [PATCH] drm/amd/display: Fix null pointer on analog detection

["Timur Kristóf" <timur.kristof@gmail.com>]

On Wed, 2025-10-29 at 12:16 -0400, Harry Wentland wrote:
> Check if we have an amdgpu_dm_connector->dc_sink first before
> adding common modes for analog outputs. If we don't have a
> sink yet we can safely skip this.

Hi Harry, nice catch!

Out of curiosity, how is it possible to reach this code when the
dc_sink is NULL?

The patch is:
Reviewed-by: Timur Kristóf <timur.kristof@gmail.com>

> 
> Fixes: 0c9f9ca99238 ("drm/amd/display: Add common modes to analog
> displays without EDID")
> Cc: Timur Kristóf <timur.kristof@gmail.com>
> Signed-off-by: Harry Wentland <harry.wentland@amd.com>
> ---
>  drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> index c621e50f636a..bc5a8b8442a2 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> @@ -8669,7 +8669,7 @@ static int amdgpu_dm_connector_get_modes(struct
> drm_connector *connector)
>  			amdgpu_dm_connector->num_modes +=
>  				drm_add_modes_noedid(connector,
> 1920, 1080);
>  
> -		if (amdgpu_dm_connector->dc_sink->edid_caps.analog)
> {
> +		if (amdgpu_dm_connector->dc_sink &&
> amdgpu_dm_connector->dc_sink->edid_caps.analog) {
>  			/* Analog monitor connected by DAC load
> detection.
>  			 * Add common modes. It will be up to the
> user to select one that works.
>  			 */