Commit e3419e1e authored by Michael Strauss's avatar Michael Strauss Committed by Alex Deucher
Browse files

drm/amd/display: Increase AUX Intra-Hop Done Max Wait Duration 



[WHY]
In the worst case, AUX intra-hop done can take hundreds of milliseconds as
each retimer in a link might have to wait a full AUX_RD_INTERVAL to send
LT abort downstream.

[HOW]
Wait 300ms for each retimer in a link to allow time to propagate a LT abort
without infinitely waiting on intra-hop done.
For no-retimer case, keep the max duration at 10ms.

Reviewed-by: default avatarWenjing Liu <wenjing.liu@amd.com>
Signed-off-by: default avatarMichael Strauss <michael.strauss@amd.com>
Signed-off-by: default avatarIvan Lipski <ivan.lipski@amd.com>
Tested-by: default avatarDaniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 9a885f11

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

+7 −2
Original line number Diff line number Diff line
@@ -1018,7 +1018,12 @@ static enum link_training_result dpcd_exit_training_mode(struct dc_link *link, e 
{

	enum dc_status status;

	uint8_t sink_status = 0;

	uint8_t i;

	uint32_t i;

	uint8_t lttpr_count = dp_parse_lttpr_repeater_count(link->dpcd_caps.lttpr_caps.phy_repeater_cnt);

	uint32_t intra_hop_disable_time_ms = (lttpr_count > 0 ? lttpr_count * 300 : 10);



	// Each hop could theoretically take over 256ms (max 128b/132b AUX RD INTERVAL)

	// To be safe, allow 300ms per LTTPR and 10ms for no LTTPR case



	/* clear training pattern set */

	status = dpcd_set_training_pattern(link, DP_TRAINING_PATTERN_VIDEOIDLE);
@@ -1028,7 +1033,7 @@ static enum link_training_result dpcd_exit_training_mode(struct dc_link *link, e 


	if (encoding == DP_128b_132b_ENCODING) {

		/* poll for intra-hop disable */

		for (i = 0; i < 10; i++) {

		for (i = 0; i < intra_hop_disable_time_ms; i++) {

			if ((core_link_read_dpcd(link, DP_SINK_STATUS, &sink_status, 1) == DC_OK) &&

					(sink_status & DP_INTRA_HOP_AUX_REPLY_INDICATION) == 0)

				break;