Commit 800de20b authored by Wenjing Liu's avatar Wenjing Liu Committed by Alex Deucher
Browse files

drm/amd/display: add a debug option to force dp2 lt fallback method 



[why]
A debug option is needed to temporarily force dp2 new link training
fallback method for debugging purpose.

Reviewed-by: default avatarGeorge Shen <George.Shen@amd.com>
Acked-by: default avatarPavle Kotarac <Pavle.Kotarac@amd.com>
Signed-off-by: default avatarWenjing Liu <wenjing.liu@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent eb9e59eb

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

+6 −3
Original line number Diff line number Diff line
@@ -100,6 +100,7 @@ static const struct dp_lt_fallback_entry dp_lt_fallbacks[] = { 
#endif



static bool decide_fallback_link_setting(

		struct dc_link *link,

		struct dc_link_settings initial_link_settings,

		struct dc_link_settings *current_link_setting,

		enum link_training_result training_result);
@@ -2609,7 +2610,7 @@ bool perform_link_training_with_retries( 
			uint32_t req_bw;

			uint32_t link_bw;



			decide_fallback_link_setting(*link_setting, &current_setting, status);

			decide_fallback_link_setting(link, *link_setting, &current_setting, status);

			/* Fail link training if reduced link bandwidth no longer meets

			 * stream requirements.

			 */
@@ -3124,7 +3125,7 @@ bool dp_verify_link_cap( 
		 * based on the actual mode we're driving

		 */

		dp_disable_link_phy(link, link->connector_signal);

	} while (!success && decide_fallback_link_setting(

	} while (!success && decide_fallback_link_setting(link,

			initial_link_settings, cur, status));



	/* Link Training failed for all Link Settings
@@ -3376,6 +3377,7 @@ static bool decide_fallback_link_setting_max_bw_policy( 
 *					and no further fallback could be done

 */

static bool decide_fallback_link_setting(

		struct dc_link *link,

		struct dc_link_settings initial_link_settings,

		struct dc_link_settings *current_link_setting,

		enum link_training_result training_result)
@@ -3383,7 +3385,8 @@ static bool decide_fallback_link_setting( 
	if (!current_link_setting)

		return false;

#if defined(CONFIG_DRM_AMD_DC_DCN)

	if (dp_get_link_encoding_format(&initial_link_settings) == DP_128b_132b_ENCODING)

	if (dp_get_link_encoding_format(&initial_link_settings) == DP_128b_132b_ENCODING ||

			link->dc->debug.force_dp2_lt_fallback_method)

		return decide_fallback_link_setting_max_bw_policy(&initial_link_settings,

				current_link_setting);

#endif

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

+1 −0
Original line number Diff line number Diff line
@@ -691,6 +691,7 @@ struct dc_debug_options { 
	/* TODO - remove once tested */

	bool legacy_dp2_lt;

	bool set_mst_en_for_sst;

	bool force_dp2_lt_fallback_method;

#endif

	union mem_low_power_enable_options enable_mem_low_power;

	union root_clock_optimization_options root_clock_optimization;