Commit 4b169ca3 authored by Jimmy Kizito's avatar Jimmy Kizito Committed by Alex Deucher
Browse files

drm/amd/display: Add workaround flag for EDID read on certain docks 



[Why]
Certain docks appear to NAK I2C writes to the segment pointer with the
MOT (middle of transaction) bit clear. This behaviour can cause EDID
reads from higher segments to fail.

[How]
Add workaround flag for links which connect to docks exhibiting this
issue.

Cc: Wayne Lin <wayne.lin@amd.com>
Reviewed-by: default avatarJun Lei <Jun.Lei@amd.com>
Acked-by: default avatarRodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Tested-by: default avatarDaniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: default avatarJimmy Kizito <Jimmy.Kizito@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 3137f792

drivers/gpu/drm/amd/display/dc/core/dc_link.c

+3 −0
Original line number Diff line number Diff line
@@ -1765,6 +1765,9 @@ static bool dc_link_construct_dpia(struct dc_link *link, 


	link->psr_settings.psr_version = DC_PSR_VERSION_UNSUPPORTED;



	/* Some docks seem to NAK I2C writes to segment pointer with mot=0. */

	link->wa_flags.dp_mot_reset_segment = true;



	return true;



ddc_create_fail:

drivers/gpu/drm/amd/display/dc/dc_link.h

+1 −0
Original line number Diff line number Diff line
@@ -190,6 +190,7 @@ struct dc_link { 
		bool dp_keep_receiver_powered;

		bool dp_skip_DID2;

		bool dp_skip_reset_segment;

		bool dp_mot_reset_segment;

	} wa_flags;

	struct link_mst_stream_allocation_table mst_stream_alloc_table;