drm/amd/display: Exclude the MST overhead from BW deallocation

[Why]
The MST overhead was incorrectly included
in the requested BW during BW deallocation.

[How]
Exclude the MST overhead from BW deallocation.

Reviewed-by: Wenjing Liu <wenjing.liu@amd.com>
Reviewed-by: Meenakshikumar Somasundaram <meenakshikumar.somasundaram@amd.com>
Signed-off-by: Cruise Hung <Cruise.Hung@amd.com>
Signed-off-by: Ivan Lipski <ivan.lipski@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/display/dc/link/link_dpms.c b/drivers/gpu/drm/amd/display/dc/link/link_dpms.c
index d52155e86f0fc8156534187cfd6513b011692de5..21f64946b993bafc98830836494e64d91f6cde68 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/link/link_dpms.c
+++ b/drivers/gpu/drm/amd/display/dc/link/link_dpms.c
@@ -2097,10 +2097,10 @@ static enum dc_status enable_link(
        return status;
 }
 
-static bool allocate_usb4_bandwidth_for_stream(struct dc_stream_state *stream, int bw)
+static bool allocate_usb4_bandwidth_for_stream(struct dc_stream_state *stream, int stream_bw)
 {
        struct dc_link *link = stream->sink->link;
-       int req_bw = bw;
+       int req_bw = stream_bw;
 
        DC_LOGGER_INIT(link->ctx->logger);
 
@@ -2108,39 +2108,38 @@ static bool allocate_usb4_bandwidth_for_stream(struct dc_stream_state *stream, i
                return false;
 
        if (stream->signal == SIGNAL_TYPE_DISPLAY_PORT_MST) {
-               int sink_index = 0;
+               int sink_index = -1;
                unsigned int i = 0;
 
                for (i = 0; i < link->sink_count; i++) {
                        if (link->remote_sinks[i] == NULL)
                                continue;
 
-                       if (stream->sink->sink_id != link->remote_sinks[i]->sink_id)
+                       if (stream->sink->sink_id != link->remote_sinks[i]->sink_id) {
+                               DC_LOG_DEBUG("%s: add remote_sink=%s, request_bw=%d\n", __func__,
+                                       (const char *)(&link->remote_sinks[i]->edid_caps.display_name[0]),
+                                       link->dpia_bw_alloc_config.remote_sink_req_bw[i]);
+
                                req_bw += link->dpia_bw_alloc_config.remote_sink_req_bw[i];
-                       else
+                       } else
                                sink_index = i;
                }
 
-               link->dpia_bw_alloc_config.remote_sink_req_bw[sink_index] = bw;
-       }
+               if (sink_index >= 0)
+                       link->dpia_bw_alloc_config.remote_sink_req_bw[sink_index] = stream_bw;
+               else
+                       DC_LOG_WARNING("%s: stream sink_id=%u not found in remote_sinks[]\n",
+                               __func__, stream->sink->sink_id);
 
-       link->dpia_bw_alloc_config.dp_overhead = link_dpia_get_dp_overhead(link);
-       req_bw += link->dpia_bw_alloc_config.dp_overhead;
+               if (req_bw) {
+                       link->dpia_bw_alloc_config.dp_overhead = link_dpia_get_dp_overhead(link);
+                       req_bw += link->dpia_bw_alloc_config.dp_overhead;
+               } else
+                       link->dpia_bw_alloc_config.dp_overhead = 0;
+       }
 
        link_dp_dpia_allocate_usb4_bandwidth_for_stream(link, req_bw);
 
-       if (stream->signal == SIGNAL_TYPE_DISPLAY_PORT_MST) {
-               unsigned int i = 0;
-
-               for (i = 0; i < link->sink_count; i++) {
-                       if (link->remote_sinks[i] == NULL)
-                               continue;
-                       DC_LOG_DEBUG("%s, remote_sink=%s, request_bw=%d\n", __func__,
-                                       (const char *)(&link->remote_sinks[i]->edid_caps.display_name[0]),
-                                       link->dpia_bw_alloc_config.remote_sink_req_bw[i]);
-               }
-       }
-
        return true;
 }