[PATCH] drm/amd/display: Fix programming backlight on OLED panels

[Harry Wentland]

On 2024-11-27 22:22, Mario Limonciello wrote:
> From: Mario Limonciello <mario.limonciello at amd.com>
> 
> commit 38077562e0594 ("drm/amd/display: Implement new
> backlight_level_params structure") adjusted DC core to require
> the backlight type to be programmed in the dc link when changing
> brightness.  This isn't initialized in amdgpu_dm for OLED panels
> though which broke brightness.
> 
> Explicitly initialize when aux support is enabled.
> 
> Reported-and-tested-by: Luke Jones <luke at ljones.dev>
> Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3792
> Fixes: 38077562e059 ("drm/amd/display: Implement new backlight_level_params structure")
> Signed-off-by: Mario Limonciello <mario.limonciello at amd.com>

Reviewed-by: Harry Wentland <harry.wentland at amd.com>

Harry

> ---
>  drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> 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 19a58630e7740..243cee2841312 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> @@ -3483,6 +3483,8 @@ static void update_connector_ext_caps(struct amdgpu_dm_connector *aconnector)
>  		caps->aux_support = false;
>  	else if (amdgpu_backlight == 1)
>  		caps->aux_support = true;
> +	if (caps->aux_support)
> +		aconnector->dc_link->backlight_control_type = BACKLIGHT_CONTROL_AMD_AUX;
>  
>  	luminance_range = &conn_base->display_info.luminance_range;
>