Commit 4de0bfe6 authored by Jimmy Kizito's avatar Jimmy Kizito Committed by Alex Deucher
Browse files

drm/amd/display: Fix link training fallback logic 



[Why]
Link training should fail if stream bandwidth exceeds link bandwidth.

[How]
Correct fallback logic and use named variables to make intention clear.

Reviewed-by: default avatarMeenakshikumar Somasundaram <meenakshikumar.somasundaram@amd.com>
Reviewed-by: default avatarJun Lei <Jun.Lei@amd.com>
Acked-by: default avatarRodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: default avatarJimmy Kizito <Jimmy.Kizito@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 4b7786d8

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

+6 −2
Original line number Diff line number Diff line
@@ -2462,12 +2462,16 @@ bool perform_link_training_with_retries( 
			if (type == dc_connection_none)

				break;

		} else if (do_fallback) {

			uint32_t req_bw;

			uint32_t link_bw;



			decide_fallback_link_setting(*link_setting, &current_setting, status);

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

			 * stream requirements.

			 */

			if (dc_bandwidth_in_kbps_from_timing(&stream->timing) <

					dc_link_bandwidth_kbps(link, &current_setting))

			req_bw = dc_bandwidth_in_kbps_from_timing(&stream->timing);

			link_bw = dc_link_bandwidth_kbps(link, &current_setting);

			if (req_bw > link_bw)

				break;

		}