drm/amd/display: Ext displays with dock can't recognized after resume

[ Upstream commit 1e5d4d8eb8c0f15d90c50e7abd686c980e54e42e ]

[Why]
Needs to set the default value of the LTTPR timeout after resume.

[How]
Set the default (3.2ms) timeout at resuming if the sink supports
LTTPR

Reviewed-by: Jerry Zuo <Jerry.Zuo@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Ryan Lin <tsung-hua.lin@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/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 422909d1f352ba3df9e5d60ded92c238c39d7398..58fdd39f5bde95013214b9105d16cb178ca701f1 100644 (file)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -39,6 +39,7 @@
 #include "dc/dc_edid_parser.h"
 #include "dc/dc_stat.h"
 #include "amdgpu_dm_trace.h"
+#include "dc/inc/dc_link_ddc.h"
 
 #include "vid.h"
 #include "amdgpu.h"
@@ -2262,6 +2263,14 @@ static void s3_handle_mst(struct drm_device *dev, bool suspend)
                if (suspend) {
                        drm_dp_mst_topology_mgr_suspend(mgr);
                } else {
+                       /* if extended timeout is supported in hardware,
+                        * default to LTTPR timeout (3.2ms) first as a W/A for DP link layer
+                        * CTS 4.2.1.1 regression introduced by CTS specs requirement update.
+                        */
+                       dc_link_aux_try_to_configure_timeout(aconnector->dc_link->ddc, LINK_AUX_DEFAULT_LTTPR_TIMEOUT_PERIOD);
+                       if (!dp_is_lttpr_present(aconnector->dc_link))
+                               dc_link_aux_try_to_configure_timeout(aconnector->dc_link->ddc, LINK_AUX_DEFAULT_TIMEOUT_PERIOD);
+
                        ret = drm_dp_mst_topology_mgr_resume(mgr, true);
                        if (ret < 0) {
                                dm_helpers_dp_mst_stop_top_mgr(aconnector->dc_link->ctx,