Re: [PATCH 09/18] drm/amd/display: Create fake sink and stream for writeback connector

[Alex Hung <alex.hung@xxxxxxx>]

Reviewed-by: Alex Hung <alex.hung@xxxxxxx>

On 2023-08-16 15:26, Alex Hung wrote:
> From: Harry Wentland <harry.wentland@xxxxxxx>
>
> [WHAT]
> Writeback connectors don't have a physical sink but DC still
> needs a sink to function. Create a fake sink and stream for
> writeback connectors
>
> Signed-off-by: Harry Wentland <harry.wentland@xxxxxxx>
> Signed-off-by: Alex Hung <alex.hung@xxxxxxx>
> ---
>   .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 33 ++++++++++++-------
>   1 file changed, 22 insertions(+), 11 deletions(-)
>
> 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 b12e8393fef3..82f00af14ada 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> @@ -5611,13 +5611,13 @@ decide_crtc_timing_for_drm_display_mode(struct drm_display_mode *drm_mode,
>   }
>   
>   static struct dc_sink *
> -create_fake_sink(struct amdgpu_dm_connector *aconnector)
> +create_fake_sink(struct dc_link *link)
>   {
>   	struct dc_sink_init_data sink_init_data = { 0 };
>   	struct dc_sink *sink = NULL;
>   
> -	sink_init_data.link = aconnector->dc_link;
> -	sink_init_data.sink_signal = aconnector->dc_link->connector_signal;
> +	sink_init_data.link = link;
> +	sink_init_data.sink_signal = link->connector_signal;
>   
>   	sink = dc_sink_create(&sink_init_data);
>   	if (!sink) {
> @@ -5988,6 +5988,7 @@ create_stream_for_sink(struct drm_connector *connector,
>   	enum color_transfer_func tf = TRANSFER_FUNC_UNKNOWN;
>   	struct dsc_dec_dpcd_caps dsc_caps;
>   
> +	struct dc_link *link = NULL;
>   	struct dc_sink *sink = NULL;
>   
>   	drm_mode_init(&mode, drm_mode);
> @@ -6001,14 +6002,24 @@ create_stream_for_sink(struct drm_connector *connector,
>   	if (connector->connector_type != DRM_MODE_CONNECTOR_WRITEBACK) {
>   		aconnector = NULL;
>   		aconnector = to_amdgpu_dm_connector(connector);
> -		if (!aconnector->dc_sink) {
> -			sink = create_fake_sink(aconnector);
> -			if (!sink)
> -				return stream;
> -		} else {
> -			sink = aconnector->dc_sink;
> -			dc_sink_retain(sink);
> -		}
> +		link = aconnector->dc_link;
> +	} else {
> +		struct drm_writeback_connector *wbcon = NULL;
> +		struct amdgpu_dm_wb_connector *dm_wbcon = NULL;
> +
> +		wbcon = drm_connector_to_writeback(connector);
> +		dm_wbcon = to_amdgpu_dm_wb_connector(wbcon);
> +		link = dm_wbcon->link;
> +	}
> +
> +	if (!aconnector || !aconnector->dc_sink) {
> +		sink = create_fake_sink(link);
> +		if (!sink)
> +			return stream;
> +
> +	} else {
> +		sink = aconnector->dc_sink;
> +		dc_sink_retain(sink);
>   	}
>   
>   	stream = dc_create_stream_for_sink(sink);