drm/amd/display: not abort link train when bw is low

[ Upstream commit 8a21da2842bb22b2b80e5902d0438030d729bfd3 ]

[WHY]
DP tunneling should not abort link train even bandwidth become
too low after downgrade. Otherwise, it would fail compliance test.

[HOW}
Do link train with downgrade settings even bandwidth is not enough

Reviewed-by: Cruise Hung <cruise.hung@amd.com>
Reviewed-by: Meenakshikumar Somasundaram <meenakshikumar.somasundaram@amd.com>
Signed-off-by: Peichen Huang <PeiChen.Huang@amd.com>
Signed-off-by: Tom Chung <chiahsuan.chung@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.c
index 751c18e592ea5ef1cd774de0dbf687a38f011ec1..7848ddb94456c5924fb52a61cb013173cbffc438 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.c
+++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.c
@@ -1782,13 +1782,10 @@ 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);