Commit fa3c5a8e authored by Cruise's avatar Cruise Committed by Alex Deucher
Browse files

drm/amd/display: Not fallback if link BW is smaller than req BW 



[Why]
When the link BW is smaller than the request BW,
the DP LT just kept running and fallback to lower link config.
DP LT just aborted if is_hpd_pending bit is high.
But is_hpd_pending bit indicates a new HPD event received.
It doesn't mean the HPD is low.

[How]
Abort the DP LT if the link BW is smaller than the request BW.
Remove checking is_hpd_pending bit in DP LT.

Reviewed-by: default avatarWenjing Liu <wenjing.liu@amd.com>
Acked-by: default avatarRoman Li <roman.li@amd.com>
Signed-off-by: default avatarCruise <cruise.hung@amd.com>
Tested-by: default avatarDaniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 79d92dba

drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.c

+4 −1
Original line number Diff line number Diff line
@@ -1704,10 +1704,13 @@ bool perform_link_training_with_retries( 
			is_link_bw_min = ((cur_link_settings.link_rate <= LINK_RATE_LOW) &&

				(cur_link_settings.lane_count <= LANE_COUNT_ONE));



			if (is_link_bw_low)

			if (is_link_bw_low) {

				DC_LOG_WARNING(

					"%s: Link(%d) bandwidth too low after fallback req_bw(%d) > link_bw(%d)\n",

					__func__, link->link_index, req_bw, link_bw);



				return false;

			}

		}



		msleep(delay_between_attempts);

drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training_dpia.c

+0 −16
Original line number Diff line number Diff line
@@ -430,10 +430,6 @@ static enum link_training_result dpia_training_cr_non_transparent( 
		retry_count++;

	}



	/* Abort link training if clock recovery failed due to HPD unplug. */

	if (link->is_hpd_pending)

		result = LINK_TRAINING_ABORT;



	DC_LOG_HW_LINK_TRAINING(

		"%s\n DPIA(%d) clock recovery\n -hop(%d)\n - result(%d)\n - retries(%d)\n - status(%d)\n",

		__func__,
@@ -537,10 +533,6 @@ static enum link_training_result dpia_training_cr_transparent( 
		retry_count++;

	}



	/* Abort link training if clock recovery failed due to HPD unplug. */

	if (link->is_hpd_pending)

		result = LINK_TRAINING_ABORT;



	DC_LOG_HW_LINK_TRAINING("%s\n DPIA(%d) clock recovery\n -hop(%d)\n - result(%d)\n - retries(%d)\n",

		__func__,

		link->link_id.enum_id - ENUM_ID_1,
@@ -731,10 +723,6 @@ static enum link_training_result dpia_training_eq_non_transparent( 
				lt_settings->hw_lane_settings, lt_settings->dpcd_lane_settings);

	}



	/* Abort link training if equalization failed due to HPD unplug. */

	if (link->is_hpd_pending)

		result = LINK_TRAINING_ABORT;



	DC_LOG_HW_LINK_TRAINING(

		"%s\n DPIA(%d) equalization\n - hop(%d)\n - result(%d)\n - retries(%d)\n - status(%d)\n",

		__func__,
@@ -822,10 +810,6 @@ static enum link_training_result dpia_training_eq_transparent( 
				lt_settings->hw_lane_settings, lt_settings->dpcd_lane_settings);

	}



	/* Abort link training if equalization failed due to HPD unplug. */

	if (link->is_hpd_pending)

		result = LINK_TRAINING_ABORT;



	DC_LOG_HW_LINK_TRAINING("%s\n DPIA(%d) equalization\n - hop(%d)\n - result(%d)\n - retries(%d)\n",

		__func__,

		link->link_id.enum_id - ENUM_ID_1,