drm/amd/display: Fix DP MST sinks removal issue

From Cruise Hung
ee9caccc5e5cc1092baf6fb645525bba668b01c1 in linux-6.1.y/6.1.22
cbd6c1b17d3b42b7935526a86ad5f66838767d03 in mainline linux

diff --git a/sys/dev/pci/drm/amd/display/dc/core/dc_link.c b/sys/dev/pci/drm/amd/display/dc/core/dc_link.c
index 5edcc9b..444a999 100644 (file)
--- a/sys/dev/pci/drm/amd/display/dc/core/dc_link.c
+++ b/sys/dev/pci/drm/amd/display/dc/core/dc_link.c
@@ -1016,6 +1016,7 @@ static bool detect_link_and_local_sink(struct dc_link *link,
        struct dc_sink *prev_sink = NULL;
        struct dpcd_caps prev_dpcd_caps;
        enum dc_connection_type new_connection_type = dc_connection_none;
+       enum dc_connection_type pre_connection_type = link->type;
        const uint32_t post_oui_delay = 30; // 30ms
 
        DC_LOGGER_INIT(link->ctx->logger);
@@ -1118,6 +1119,8 @@ static bool detect_link_and_local_sink(struct dc_link *link,
                        }
 
                        if (!detect_dp(link, &sink_caps, reason)) {
+                               link->type = pre_connection_type;
+
                                if (prev_sink)
                                        dc_sink_release(prev_sink);
                                return false;
@@ -1349,6 +1352,8 @@ bool dc_link_detect(struct dc_link *link, enum dc_detect_reason reason)
        bool is_delegated_to_mst_top_mgr = false;
        enum dc_connection_type pre_link_type = link->type;
 
+       DC_LOGGER_INIT(link->ctx->logger);
+
        is_local_sink_detect_success = detect_link_and_local_sink(link, reason);
 
        if (is_local_sink_detect_success && link->local_sink)
@@ -1359,6 +1364,10 @@ bool dc_link_detect(struct dc_link *link, enum dc_detect_reason reason)
                        link->dpcd_caps.is_mst_capable)
                is_delegated_to_mst_top_mgr = discover_dp_mst_topology(link, reason);
 
+       DC_LOG_DC("%s: link_index=%d is_local_sink_detect_success=%d pre_link_type=%d link_type=%d\n", __func__,
+                link->link_index, is_local_sink_detect_success, pre_link_type, link->type);
+
+
        if (is_local_sink_detect_success &&
                        pre_link_type == dc_connection_mst_branch &&
                        link->type != dc_connection_mst_branch)