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

[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>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -41,6 +41,8 @@
 #include "dpcd_defs.h"
 #include "link/protocols/link_dpcd.h"
 #include "link_service_types.h"
+#include "link/protocols/link_dp_capability.h"
+#include "link/protocols/link_ddc.h"
 
 #include "vid.h"
 #include "amdgpu.h"
@@ -2302,6 +2304,14 @@ 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.
+			 */
+			try_to_configure_aux_timeout(aconnector->dc_link->ddc, LINK_AUX_DEFAULT_LTTPR_TIMEOUT_PERIOD);
+			if (!dp_is_lttpr_present(aconnector->dc_link))
+				try_to_configure_aux_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,

drivers/gpu/drm/amd/display/dc/link/protocols/link_ddc.h

@@ -33,6 +33,7 @@
 #define DPVGA_DONGLE_AUX_DEFER_WA_DELAY 40
 #define I2C_OVER_AUX_DEFER_WA_DELAY_1MS 1
 #define LINK_AUX_DEFAULT_LTTPR_TIMEOUT_PERIOD 3200 /*us*/
+#define LINK_AUX_DEFAULT_TIMEOUT_PERIOD 552 /*us*/
 
 #define EDID_SEGMENT_SIZE 256
 

drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c

@@ -60,8 +60,6 @@
 #define MIN(X, Y) ((X) < (Y) ? (X) : (Y))
 #endif
 
-#define LINK_AUX_DEFAULT_TIMEOUT_PERIOD 552 /*us*/
-
 struct dp_lt_fallback_entry {
 	enum dc_lane_count lane_count;
 	enum dc_link_rate link_rate;