[PATCH v1] drm/amd/display: Add DP-HDMI PCON SST Support

[Kazlauskas, Nicholas]

On 2021-11-24 12:28 p.m., Fangzhi Zuo wrote:
> 1. Parse DSC caps from PCON DPCD
> 2. Determine policy if decoding DSC at PCON
> 3. Enable/disable DSC at PCON
> 
> Signed-off-by: Fangzhi Zuo <Jerry.Zuo at amd.com>

Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas at amd.com>

Regards,
Nicholas Kazlauskas

> ---
>   .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 41 +++++++++++++++----
>   .../amd/display/amdgpu_dm/amdgpu_dm_helpers.c | 13 +++++-
>   2 files changed, 44 insertions(+), 10 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 9a1ac657faa2..9dbf6bf3f1c3 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> @@ -6047,10 +6047,12 @@ static void update_dsc_caps(struct amdgpu_dm_connector *aconnector,
>   
>   	if (aconnector->dc_link && (sink->sink_signal == SIGNAL_TYPE_DISPLAY_PORT ||
>   		sink->sink_signal == SIGNAL_TYPE_EDP)) {
> -		dc_dsc_parse_dsc_dpcd(aconnector->dc_link->ctx->dc,
> -				      aconnector->dc_link->dpcd_caps.dsc_caps.dsc_basic_caps.raw,
> -				      aconnector->dc_link->dpcd_caps.dsc_caps.dsc_branch_decoder_caps.raw,
> -				      dsc_caps);
> +		if (sink->link->dpcd_caps.dongle_type == DISPLAY_DONGLE_NONE ||
> +			sink->link->dpcd_caps.dongle_type == DISPLAY_DONGLE_DP_HDMI_CONVERTER)
> +			dc_dsc_parse_dsc_dpcd(aconnector->dc_link->ctx->dc,
> +				aconnector->dc_link->dpcd_caps.dsc_caps.dsc_basic_caps.raw,
> +				aconnector->dc_link->dpcd_caps.dsc_caps.dsc_branch_decoder_caps.raw,
> +				dsc_caps);
>   	}
>   }
>   
> @@ -6120,6 +6122,8 @@ static void apply_dsc_policy_for_stream(struct amdgpu_dm_connector *aconnector,
>   	uint32_t link_bandwidth_kbps;
>   	uint32_t max_dsc_target_bpp_limit_override = 0;
>   	struct dc *dc = sink->ctx->dc;
> +	uint32_t max_supported_bw_in_kbps, timing_bw_in_kbps;
> +	uint32_t dsc_max_supported_bw_in_kbps;
>   
>   	link_bandwidth_kbps = dc_link_bandwidth_kbps(aconnector->dc_link,
>   							dc_link_get_link_cap(aconnector->dc_link));
> @@ -6138,16 +6142,37 @@ static void apply_dsc_policy_for_stream(struct amdgpu_dm_connector *aconnector,
>   		apply_dsc_policy_for_edp(aconnector, sink, stream, dsc_caps, max_dsc_target_bpp_limit_override);
>   
>   	} else if (aconnector->dc_link && sink->sink_signal == SIGNAL_TYPE_DISPLAY_PORT) {
> -
> -		if (dc_dsc_compute_config(aconnector->dc_link->ctx->dc->res_pool->dscs[0],
> +		if (sink->link->dpcd_caps.dongle_type == DISPLAY_DONGLE_NONE) {
> +			if (dc_dsc_compute_config(aconnector->dc_link->ctx->dc->res_pool->dscs[0],
>   						dsc_caps,
>   						aconnector->dc_link->ctx->dc->debug.dsc_min_slice_height_override,
>   						max_dsc_target_bpp_limit_override,
>   						link_bandwidth_kbps,
>   						&stream->timing,
>   						&stream->timing.dsc_cfg)) {
> -			stream->timing.flags.DSC = 1;
> -			DRM_DEBUG_DRIVER("%s: [%s] DSC is selected from SST RX\n", __func__, drm_connector->name);
> +				stream->timing.flags.DSC = 1;
> +				DRM_DEBUG_DRIVER("%s: [%s] DSC is selected from SST RX\n",
> +								 __func__, drm_connector->name);
> +			}
> +		} else if (sink->link->dpcd_caps.dongle_type == DISPLAY_DONGLE_DP_HDMI_CONVERTER) {
> +			timing_bw_in_kbps = dc_bandwidth_in_kbps_from_timing(&stream->timing);
> +			max_supported_bw_in_kbps = link_bandwidth_kbps;
> +			dsc_max_supported_bw_in_kbps = link_bandwidth_kbps;
> +
> +			if (timing_bw_in_kbps > max_supported_bw_in_kbps &&
> +					max_supported_bw_in_kbps > 0 &&
> +					dsc_max_supported_bw_in_kbps > 0)
> +				if (dc_dsc_compute_config(aconnector->dc_link->ctx->dc->res_pool->dscs[0],
> +						dsc_caps,
> +						aconnector->dc_link->ctx->dc->debug.dsc_min_slice_height_override,
> +						max_dsc_target_bpp_limit_override,
> +						dsc_max_supported_bw_in_kbps,
> +						&stream->timing,
> +						&stream->timing.dsc_cfg)) {
> +					stream->timing.flags.DSC = 1;
> +					DRM_DEBUG_DRIVER("%s: [%s] DSC is selected from DP-HDMI PCON\n",
> +									 __func__, drm_connector->name);
> +				}
>   		}
>   	}
>   
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
> index e8e70840a622..2c73594da85f 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
> @@ -585,8 +585,17 @@ bool dm_helpers_dp_write_dsc_enable(
>   	}
>   
>   	if (stream->signal == SIGNAL_TYPE_DISPLAY_PORT || stream->signal == SIGNAL_TYPE_EDP) {
> -		ret = dm_helpers_dp_write_dpcd(ctx, stream->link, DP_DSC_ENABLE, &enable_dsc, 1);
> -		DC_LOG_DC("Send DSC %s to sst display\n", enable_dsc ? "enable" : "disable");
> +#if defined(CONFIG_DRM_AMD_DC_DCN)
> +		if (stream->sink->link->dpcd_caps.dongle_type == DISPLAY_DONGLE_NONE) {
> +#endif
> +			ret = dm_helpers_dp_write_dpcd(ctx, stream->link, DP_DSC_ENABLE, &enable_dsc, 1);
> +			DC_LOG_DC("Send DSC %s to SST RX\n", enable_dsc ? "enable" : "disable");
> +#if defined(CONFIG_DRM_AMD_DC_DCN)
> +		} else if (stream->sink->link->dpcd_caps.dongle_type == DISPLAY_DONGLE_DP_HDMI_CONVERTER) {
> +			ret = dm_helpers_dp_write_dpcd(ctx, stream->link, DP_DSC_ENABLE, &enable_dsc, 1);
> +			DC_LOG_DC("Send DSC %s to DP-HDMI PCON\n", enable_dsc ? "enable" : "disable");
> +		}
> +#endif
>   	}
>   
>   	return (ret > 0);
>