chore: release v0.27.12

internal/rigctld/rigctld.go

@@ -262,7 +262,18 @@ func (s *Server) serve(c net.Conn) {
 			return
 		}
 		req := strings.TrimSpace(line)
+		started := time.Now()
 		resp, quit := s.handle(req)
+		// A command the radio took a visible time to accept is worth a line of its
+		// own, always — not behind the trace switch below.
+		//
+		// This is the shape every "WSJT-X takes ten seconds to change band" report
+		// has: the client is waiting on us, we are waiting on the rig, and the log
+		// showed neither. Which command, and how long, is the whole diagnosis —
+		// and one second is already far outside anything a healthy link does.
+		if took := time.Since(started); took > time.Second && req != "" {
+			s.log("rigctld: %q took %s — the radio was slow to answer, the client waited that long", req, took.Round(10*time.Millisecond))
+		}
 		// The whole exchange, when tracing is on.
 		//
 		// Only PTT transitions were ever recorded, so when JTDX aborted a
@@ -362,6 +373,21 @@ func (s *Server) handle(line string) (resp string, quit bool) {
 		if len(args) < 1 {
 			return rprt(-1), false
 		}
+		// Only touch the radio on a CHANGE, the same rule set_ptt above follows.
+		//
+		// WSJT-X restates the mode on every band change and after every transmit,
+		// almost always the mode the rig is already in. On a native backend that
+		// is not free: an Icom set_mode is the mode frame, the data-mode frame and
+		// a readback to check the rig honoured them, each a round trip — over a
+		// remote CI-V link that is seconds, spent to arrive where we already were,
+		// with the client blocked on the answer the whole time.
+		//
+		// Compared in the CLIENT's own vocabulary — what "m" would report against
+		// what it just asked for — so nothing it can observe changes. A rig whose
+		// mode we do not know yet (empty) is never assumed.
+		if cur := s.rig.Mode(); cur != "" && adifToHamlib(cur) == adifToHamlib(hamlibToADIF(args[0])) {
+			return rprt(0), false
+		}
 		if err := s.rig.SetMode(hamlibToADIF(args[0])); err != nil {
 			s.log("rigctld: set_mode %q failed: %v", args[0], err)
 			return rprt(-9), false