Re: drm/amd/display: explicitly disable psr_feature_enable appropriately

["Limonciello, Mario" <mario.limonciello@xxxxxxx>]

On 10/6/2022 23:28, Shirish S wrote:
> [Why]
> If psr_feature_enable is set to true by default, it continues to be enabled
> for non capable links.
>
> [How]
> explicitly disable the feature on links that are not capable of the same.
>
> Signed-off-by: Shirish S <shirish.s@xxxxxxx>
> Reviewed-by: Leo Li <sunpeng.li@xxxxxxx>

This has been a problem potentially all the way to when PSR was first added.

I think this should probably go back to stable.  The commit that last 
touched it (f4594cd1fa556) was in 5.13, but this could at least be fixed 
in the 5.15 LTS kernel and newer.

Cc: stable@xxxxxxxxxxxxxxx # 5.15+
Fixes: 8c322309e48e9 ("drm/amd/display: Enable PSR")
Reviewed-by: Mario Limonciello <mario.limonciello@xxxxxxx>

> ---
>   drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_psr.c | 8 ++++++--
>   1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_psr.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_psr.c
> index 8ca10ab3dfc1..26291db0a3cf 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_psr.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_psr.c
> @@ -60,11 +60,15 @@ static bool link_supports_psrsu(struct dc_link *link)
>    */
>   void amdgpu_dm_set_psr_caps(struct dc_link *link)
>   {
> -	if (!(link->connector_signal & SIGNAL_TYPE_EDP))
> +	if (!(link->connector_signal & SIGNAL_TYPE_EDP)) {
> +		link->psr_settings.psr_feature_enabled = false;
>   		return;
> +	}
>   
> -	if (link->type == dc_connection_none)
> +	if (link->type == dc_connection_none) {
> +		link->psr_settings.psr_feature_enabled = false;
>   		return;
> +	}
>   
>   	if (link->dpcd_caps.psr_info.psr_version == 0) {
>   		link->psr_settings.psr_version = DC_PSR_VERSION_UNSUPPORTED;