[PATCH] drm/amd/display: Fix OLED brightness control on eDP

[Alex Deucher]

On Wed, Nov 17, 2021 at 10:22 AM <Roman.Li at amd.com> wrote:
>
> From: Roman Li <Roman.Li at amd.com>
>
> [Why]
> After commit ("drm/amd/display: add support for multiple backlights")
> number of eDPs is defined while registering backlight device.
> However the panel's extended caps get updated once before register call.
> That leads to regression with extended caps like oled brightness control.
>
> [How]
> Update connector ext caps after register_backlight_device
>
> Fixes: b1c61212d8dc ("drm/amd/display: add support for multiple backlights")
> Link: https://www.reddit.com/r/AMDLaptops/comments/qst0fm/after_updating_to_linux_515_my_brightness/

Acked-by: Alex Deucher <alexander.deucher at amd.com>

>
> Signed-off-by: Roman Li <Roman.Li at amd.com>
> ---
>  drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 3 ++-
>  1 file changed, 2 insertions(+), 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 26fcc89..44c9994 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> @@ -4243,7 +4243,8 @@ static int amdgpu_dm_initialize_drm_device(struct amdgpu_device *adev)
>                 } else if (dc_link_detect(link, DETECT_REASON_BOOT)) {
>                         amdgpu_dm_update_connector_after_detect(aconnector);
>                         register_backlight_device(dm, link);
> -
> +                       if (dm->num_of_edps)
> +                               update_connector_ext_caps(aconnector);
>                         if (psr_feature_enabled)
>                                 amdgpu_dm_set_psr_caps(link);
>                 }
> --
> 2.7.4
>