drm/amd/display: Link training retry fix for abort case

[ Upstream commit 71ae30997a8f1791835167d3ceb8d1fab32407db ]

[Why]
If link training is aborted, it shall be retried if sink is present.

[How]
Check hpd status to find out whether sink is present or not. If sink is
present, then link training shall be tried again with same settings.
Otherwise, link training shall be aborted.

Reviewed-by: Jimmy Kizito <Jimmy.Kizito@amd.com>
Acked-by: Mikita Lipski <mikita.lipski@amd.com>
Signed-off-by: Meenakshikumar Somasundaram <meenakshikumar.somasundaram@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/core/dc_link_dp.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
index a6d0fd24fd02db28c4bed2bbf9c2ae58c59b3ad0..83ef72a3ebf413688c4c2eabffe099d295fa0e90 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
@@ -1849,9 +1849,13 @@ bool perform_link_training_with_retries(
                dp_disable_link_phy(link, signal);
 
                /* Abort link training if failure due to sink being unplugged. */
-               if (status == LINK_TRAINING_ABORT)
-                       break;
-               else if (do_fallback) {
+               if (status == LINK_TRAINING_ABORT) {
+                       enum dc_connection_type type = dc_connection_none;
+
+                       dc_link_detect_sink(link, &type);
+                       if (type == dc_connection_none)
+                               break;
+               } else if (do_fallback) {
                        decide_fallback_link_setting(*link_setting, &current_setting, status);
                        /* Fail link training if reduced link bandwidth no longer meets
                         * stream requirements.