Commit 2f2a4b18 authored by George Shen's avatar George Shen Committed by Alex Deucher
Browse files

drm/amd/display: Skip vendor specific LTTPR w/a outside link training 



[Why]
Vendor specific link rate toggle workaround should not be
applied outside of link training scenario, such as when
outputting PHY test pattern.

[How]
Add flag to indicate when link training is occuring.
Make workaround a no-op when flag is not set.

Reviewed-by: default avatarJun Lei <Jun.Lei@amd.com>
Acked-by: default avatarBhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: default avatarGeorge Shen <George.Shen@amd.com>
Tested-by: default avatarDaniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent c11099b0

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

+25 −19
Original line number Diff line number Diff line
@@ -444,6 +444,7 @@ static void vendor_specific_lttpr_wa_one_two( 
	struct dc_link *link,

	const uint8_t rate)

{

	if (link->apply_vendor_specific_lttpr_link_rate_wa) {

		uint8_t toggle_rate = 0x0;



		if (rate == 0x6)
@@ -463,6 +464,7 @@ static void vendor_specific_lttpr_wa_one_two( 
		/* Store the last attempted link rate for this link */

		link->vendor_specific_lttpr_link_rate_wa = rate;

	}

}



static void vendor_specific_lttpr_wa_three(

	struct dc_link *link,
@@ -2383,10 +2385,12 @@ enum link_training_result dc_link_dp_perform_link_training( 
	/* reset previous training states */

	if (link->dc->debug.apply_vendor_specific_lttpr_wa &&

			(link->chip_caps & EXT_DISPLAY_PATH_CAPS__DP_FIXED_VS_EN) &&

			link->lttpr_mode == LTTPR_MODE_TRANSPARENT)

			link->lttpr_mode == LTTPR_MODE_TRANSPARENT) {

		link->apply_vendor_specific_lttpr_link_rate_wa = true;

		vendor_specific_lttpr_wa_four(link, true);

	else

	} else {

		dpcd_exit_training_mode(link);

	}



	/* configure link prior to entering training mode */

	dpcd_configure_lttpr_mode(link, &lt_settings);
@@ -2409,10 +2413,12 @@ enum link_training_result dc_link_dp_perform_link_training( 
	/* exit training mode */

	if (link->dc->debug.apply_vendor_specific_lttpr_wa &&

			(link->chip_caps & EXT_DISPLAY_PATH_CAPS__DP_FIXED_VS_EN) &&

			link->lttpr_mode == LTTPR_MODE_TRANSPARENT)

			link->lttpr_mode == LTTPR_MODE_TRANSPARENT) {

		link->apply_vendor_specific_lttpr_link_rate_wa = false;

		vendor_specific_lttpr_wa_four(link, (status != LINK_TRAINING_SUCCESS));

	else

	} else {

		dpcd_exit_training_mode(link);

	}



	/* switch to video idle */

	if ((status == LINK_TRAINING_SUCCESS) || !skip_video_pattern)

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

+1 −0
Original line number Diff line number Diff line
@@ -188,6 +188,7 @@ struct dc_link { 


	/* Vendor specific LTTPR workaround variables */

	uint8_t vendor_specific_lttpr_link_rate_wa;

	bool apply_vendor_specific_lttpr_link_rate_wa;



	/* MST record stream using this link */

	struct link_flags {