Log when the node is driving the graph

Useful for debugging.

Author: DemiMarie

pipewire/qubes-pw-module.c

@@ -688,6 +688,14 @@ static int process_control_commands(struct impl *impl)
 
         pw_log_trace("Audio playback %s", new_state ? "started" : "stopped");
 
+#if QUBES_PW_CAN_DRIVE
+        if (new_state && pw_stream_is_driving(playback_stream->stream)) {
+            // If *either* stream is driving, use the playback vchan to drive
+            // the graph.  Specifically, drive the graph when there is enough
+            // space in the playback vchan for a cycle.
+            pw_log_trace("Qubes OS playback node is driving");
+        }
+#endif
         rt_set_stream_state(playback_stream, new_state);
     }
 
@@ -707,6 +715,11 @@ static int process_control_commands(struct impl *impl)
 
         pw_log_trace("Audio capturing %s", new_state ? "started" : "stopped");
 
+#if QUBES_PW_CAN_DRIVE
+        if (new_state && pw_stream_is_driving(capture_stream->stream)) {
+            pw_log_trace("Qubes OS capture node is driving");
+        }
+#endif
         rt_set_stream_state(capture_stream, new_state);
     }