Commit e7f2c80c authored by Wenjing Liu's avatar Wenjing Liu Committed by Alex Deucher
Browse files

drm/amd/display: check hpd before retry verify link cap 



[why]
During detection link training if a display is disconnected,
the current code will retry 3 times of link training
on disconnected link before giving up.

[how]
Before each retry check for HPD status, only retry
verify link cap when HPD is still high.
Also put a 10ms delay between each retry to improve
the chance of success.

Signed-off-by: default avatarWenjing Liu <Wenjing.Liu@amd.com>
Reviewed-by: default avatarJun Lei <Jun.Lei@amd.com>
Acked-by: default avatarAbdoulaye Berthe <Abdoulaye.Berthe@amd.com>
Acked-by: default avatarLeo Li <sunpeng.li@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 79e00520

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

+6 −21
Original line number Diff line number Diff line
@@ -854,16 +854,9 @@ bool dc_link_detect(struct dc_link *link, enum dc_detect_reason reason) 
					dc_sink_release(prev_sink);

				} else {

					/* Empty dongle plug in */

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

						int fail_count = 0;



						dp_verify_link_cap(link,

					dp_verify_link_cap_with_retries(link,

							&link->reported_link_cap,

								  &fail_count);



						if (fail_count == 0)

							break;

					}

							LINK_TRAINING_MAX_VERIFY_RETRY);

				}

				return true;

			}
@@ -967,17 +960,9 @@ bool dc_link_detect(struct dc_link *link, enum dc_detect_reason reason) 
			 */



			/* deal with non-mst cases */

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

				int fail_count = 0;



				dp_verify_link_cap(link,

			dp_verify_link_cap_with_retries(link,

					&link->reported_link_cap,

						  &fail_count);



				if (fail_count == 0)

					break;

			}



					LINK_TRAINING_MAX_VERIFY_RETRY);

		} else {

			// If edid is the same, then discard new sink and revert back to original sink

			if (same_edid) {

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

+27 −0
Original line number Diff line number Diff line
@@ -1643,6 +1643,33 @@ bool dp_verify_link_cap( 
	return success;

}



bool dp_verify_link_cap_with_retries(

	struct dc_link *link,

	struct dc_link_settings *known_limit_link_setting,

	int attempts)

{

	uint8_t i = 0;

	bool success = false;



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

		int fail_count = 0;

		enum dc_connection_type type;



		memset(&link->verified_link_cap, 0,

				sizeof(struct dc_link_settings));

		if (!dc_link_detect_sink(link, &type)) {

			break;

		} else if (dp_verify_link_cap(link,

				&link->reported_link_cap,

				&fail_count) && fail_count == 0) {

			success = true;

			break;

		}

		msleep(10);

	}

	return success;

}



static struct dc_link_settings get_common_supported_link_settings(

		struct dc_link_settings link_setting_a,

		struct dc_link_settings link_setting_b)

drivers/gpu/drm/amd/display/dc/inc/dc_link_dp.h

+5 −0
Original line number Diff line number Diff line
@@ -38,6 +38,11 @@ bool dp_verify_link_cap( 
	struct dc_link_settings *known_limit_link_setting,

	int *fail_count);



bool dp_verify_link_cap_with_retries(

	struct dc_link *link,

	struct dc_link_settings *known_limit_link_setting,

	int attempts);



bool dp_validate_mode_timing(

	struct dc_link *link,

	const struct dc_crtc_timing *timing);

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