Commit cf37a531 authored by Agustin Gutierrez's avatar Agustin Gutierrez Committed by Alex Deucher
Browse files

drm/amd/display: MST DSC check for older devices 



[Why]
Some older MST hubs do not report DPCD registers according to
specification.

[How]
This change re-applies commit c5365554 ("drm/amd/display: dsc mst
re-compute pbn for changes on hub").
With an additional check for these older MST devices.

Reviewed-by: default avatarSwapnil Patel <swapnil.patel@amd.com>
Acked-by: default avatarTom Chung <chiahsuan.chung@amd.com>
Signed-off-by: default avatarAgustin Gutierrez <agustin.gutierrez@amd.com>
Tested-by: default avatarDaniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent b436f1cb

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c

+8 −6
Original line number Diff line number Diff line
@@ -1219,6 +1219,12 @@ static bool is_dsc_need_re_compute( 
	if (dc_link->type != dc_connection_mst_branch)

		return false;



	/* add a check for older MST DSC with no virtual DPCDs */

	if (needs_dsc_aux_workaround(dc_link)  &&

		(!(dc_link->dpcd_caps.dsc_caps.dsc_basic_caps.fields.dsc_support.DSC_SUPPORT ||

		dc_link->dpcd_caps.dsc_caps.dsc_basic_caps.fields.dsc_support.DSC_PASSTHROUGH_SUPPORT)))

		return false;



	for (i = 0; i < MAX_PIPES; i++)

		stream_on_link[i] = NULL;
@@ -1240,12 +1246,8 @@ static bool is_dsc_need_re_compute( 
			continue;



		/*

		 *	Check if cached virtual MST DSC caps are available and DSC is supported

		 *	this change takes care of newer MST DSC capable devices that report their

		 *	DPCD caps as per specifications in their Virtual DPCD registers.



		 *	TODO: implement the check for older MST DSC devices that do not conform to

		 *	specifications.

		 *	check if cached virtual MST DSC caps are available and DSC is supported

		 *	as per specifications in their Virtual DPCD registers.

		*/

		if (!(aconnector->dc_sink->dsc_caps.dsc_dec_caps.is_dsc_supported ||

			aconnector->dc_link->dpcd_caps.dsc_caps.dsc_basic_caps.fields.dsc_support.DSC_PASSTHROUGH_SUPPORT))