[PATCH 6.1.y / PATCH 6.2.y 1/1] drm/amd/display: Ext displays with dock can't recognized after resume

[Mario Limonciello <mario.limonciello@amd.com>]

From: Ryan Lin <tsung-hua.lin@amd.com>

[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>
(cherry picked from commit 01a18aa309aec12461fb5e6aecb76f8b33810658)
Hand modified for missing changes in older kernels including rename
of dc_link_aux_try_to_configure_timeout()
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
(cherry picked from commit 5895ee73fc6b3d507b8ce42763df086acf43d26b)
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 9 +++++++++
 1 file changed, 9 insertions(+)

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 6c5ea99223ba..c5ee63862b01 100644
--- 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"
@@ -2253,6 +2254,14 @@ 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,
-- 
2.34.1