autoroute: keep Master on hardware and name the control feed from the live graph

A sink node re-created under a running Ardour left Master with no hardware
output: every unit active, the rig silent. Additive only (never prunes), off
switch TIDAL_AUTOROUTE_MASTER=0, ports taken from the graph not assumed FL/FR.
The control-surface assertion used an old PipeWire port spelling and was a
silent no-op on 1.0.5; resolve it from the live graph. One pw-link snapshot per
tick instead of three.

tools/tests/test_autoroute_master_and_control.py

+"""tidal-ardour-autoroute owns two links it used to leave to luck.
+
+2026-10-11. A sink node re-created under a running Ardour (a card toggled off and
+on) left Master with no hardware output: every unit active, the rig silent. And
+the control-surface assertion named its source port in an old PipeWire spelling
+("Midi Through: Port-0 (capture)"), so on PipeWire 1.0.5 it was a silent no-op
+and the faders only worked because Ardour had saved the link itself.
+
+Run against stub `pw-link` and `pactl` so no real graph is touched.
+"""
+from __future__ import annotations
+
+import os
+import pathlib
+import subprocess
+import textwrap
+
+SCRIPT = pathlib.Path(__file__).resolve().parents[1] / "tidal-ardour-autoroute.sh"
+
+SINK = "alsa_output.pci-0000_00_1f.3-platform-sof_sdw.HiFi__hw_sofsoundwire_2__sink"
+
+INPUTS = f"""\
+ardour:Tidal 01/audio_in 1
+ardour:Tidal 01/audio_in 2
+ardour:MIDI Control In
+{SINK}:playback_FR
+{SINK}:playback_FL
+"""
+
+CTRL_LINKED = "Midi-Bridge:Midi Through:(capture_0) Midi Through Port-0\n  |-> ardour:MIDI Control In\n"
+CTRL_UNLINKED = "Midi-Bridge:Midi Through:(capture_0) Midi Through Port-0\n"
+MASTER_DANGLING = "ardour:Master/audio_out 1\nardour:Master/audio_out 2\n"
+MASTER_ON_SPEAKER = (f"ardour:Master/audio_out 1\n  |-> {SINK}:playback_FL\n"
+                     f"ardour:Master/audio_out 2\n  |-> {SINK}:playback_FR\n")
+
+
+def _reconcile(tmp_path, lo, inputs=INPUTS, default_sink=SINK, extra_env=None):
+    stubs = tmp_path / "bin"
+    stubs.mkdir(exist_ok=True)
+    calls = tmp_path / "pw-link.calls"
+    calls.write_text("")
+    (tmp_path / "lo").write_text(lo)
+    (tmp_path / "in").write_text(inputs)
+    (stubs / "pw-link").write_text(textwrap.dedent(f"""\
+        #!/bin/sh
+        case "$1" in
+          -lo) cat '{tmp_path / "lo"}' ;;
+          -i)  cat '{tmp_path / "in"}' ;;
+          *)   echo "$@" >> '{calls}' ;;
+        esac
+        """))
+    (stubs / "pactl").write_text(f"#!/bin/sh\n[ \"$1\" = get-default-sink ] && echo '{default_sink}'\n")
+    for s in stubs.iterdir():
+        s.chmod(0o755)
+    env = dict(os.environ, PATH=f"{stubs}:{os.environ['PATH']}")
+    env.update(extra_env or {})
+    out = subprocess.run(["bash", "-c", f"source '{SCRIPT}'\nreconcile"],
+                         env=env, capture_output=True, text=True, timeout=20)
+    assert out.returncode == 0, out.stderr
+    return calls.read_text().splitlines(), out.stdout
+
+
+def test_a_dangling_master_gets_the_default_sink(tmp_path):
+    calls, out = _reconcile(tmp_path, CTRL_LINKED + MASTER_DANGLING)
+    assert f"ardour:Master/audio_out 1 {SINK}:playback_FL" in calls
+    assert f"ardour:Master/audio_out 2 {SINK}:playback_FR" in calls
+    assert "no hardware output" in out
+
+
+def test_ports_come_from_the_graph_not_from_an_assumed_FL_FR(tmp_path):
+    """An audio interface names its playback ports AUX0/AUX1."""
+    iface = "alsa_output.usb-interface.analog-stereo"
+    inputs = f"ardour:Tidal 01/audio_in 1\n{iface}:playback_AUX1\n{iface}:playback_AUX0\n"
+    calls, _ = _reconcile(tmp_path, CTRL_LINKED + MASTER_DANGLING, inputs=inputs, default_sink=iface)
+    assert f"ardour:Master/audio_out 1 {iface}:playback_AUX0" in calls
+    assert f"ardour:Master/audio_out 2 {iface}:playback_AUX1" in calls
+
+
+def test_a_master_that_already_reaches_hardware_is_left_alone(tmp_path):
+    calls, out = _reconcile(tmp_path, CTRL_LINKED + MASTER_ON_SPEAKER)
+    assert not [c for c in calls if c.startswith("ardour:Master")]
+    assert out == ""
+
+
+def test_it_never_prunes_masters_links(tmp_path):
+    """Which sinks Master feeds is the owner's call: additive only."""
+    calls, _ = _reconcile(tmp_path, CTRL_LINKED + MASTER_ON_SPEAKER)
+    assert not [c for c in calls if c.startswith("-d") and "Master" in c]
+
+
+def test_the_off_switch_is_honoured(tmp_path):
+    calls, _ = _reconcile(tmp_path, CTRL_LINKED + MASTER_DANGLING,
+                          extra_env={"TIDAL_AUTOROUTE_MASTER": "0"})
+    assert not [c for c in calls if c.startswith("ardour:Master")]
+
+
+def test_no_ardour_tracks_means_no_master_action(tmp_path):
+    """Not a performance: route nothing (a linkless jack client spins at RT)."""
+    inputs = f"ardour:MIDI Control In\n{SINK}:playback_FL\n"
+    calls, _ = _reconcile(tmp_path, CTRL_LINKED + MASTER_DANGLING, inputs=inputs)
+    assert not [c for c in calls if c.startswith("ardour:Master")]
+
+
+def test_no_default_sink_is_reported_once_not_guessed(tmp_path):
+    calls, out = _reconcile(tmp_path, CTRL_LINKED + MASTER_DANGLING, default_sink="")
+    assert not [c for c in calls if c.startswith("ardour:Master")]
+    assert "no default sink" in out
+
+
+def test_the_control_feed_is_named_from_the_live_graph(tmp_path):
+    calls, _ = _reconcile(tmp_path, CTRL_UNLINKED + MASTER_ON_SPEAKER)
+    assert ("Midi-Bridge:Midi Through:(capture_0) Midi Through Port-0 "
+            "ardour:MIDI Control In") in calls
+
+
+def test_the_old_spelling_of_the_port_still_resolves(tmp_path):
+    old = "Midi-Bridge:Midi Through: Port-0 (capture)\n"
+    calls, _ = _reconcile(tmp_path, old + MASTER_ON_SPEAKER)
+    assert "Midi-Bridge:Midi Through: Port-0 (capture) ardour:MIDI Control In" in calls
+
+
+def test_an_already_linked_control_feed_costs_no_call(tmp_path):
+    calls, _ = _reconcile(tmp_path, CTRL_LINKED + MASTER_ON_SPEAKER)
+    assert not [c for c in calls if "MIDI Control In" in c]
+
+
+def test_the_midi_through_playback_side_is_never_taken_for_the_source(tmp_path):
+    lo = "Midi-Bridge:Midi Through:(playback_0) Midi Through Port-0\n" + MASTER_ON_SPEAKER
+    calls, _ = _reconcile(tmp_path, lo)
+    assert not [c for c in calls if "MIDI Control In" in c]

tools/tidal-ardour-autoroute.sh

@@ -12,6 +12,15 @@
 #          monitoring is via Ardour Master. sclang/SuperDirt re-adds the
 #          orbit-0 monitor (out_1/out_2 -> Headphones) on (re)boot; this kills it.
 #
+#   MASTER: if Ardour Master has NO hardware output at all, link it to the
+#          default sink. Additive only, never pruning: which sinks Master feeds
+#          is the owner's call. Ardour restores its own output links only when
+#          it loads a session, so a sink node that is re-created (a card toggled
+#          off and on, a dock replugged) leaves Master dangling and the rig
+#          perfectly silent while every unit reads active. 2026-10-11.
+#   CTRL:  keep Midi Through -> ardour:MIDI Control In, with the port NAMED FROM
+#          THE LIVE GRAPH (see below).
+#
 # Track numbers are auto-detected from the live graph, so adding/removing
 # "Tidal NN" tracks in Ardour needs no edit here. pw-link "File exists" /
 # missing-port errors are expected and ignored.
@@ -33,8 +42,8 @@ tidal_track_numbers() {
 }
 
 # Print "src<TAB>dest" for every SuperCollider:out_* -> hardware playback link.
-sc_hw_playback_links() {
-    pw-link -lo 2>/dev/null | awk -v sc="$SC" '
+sc_hw_playback_links() {  # stdin: the `pw-link -lo` snapshot
+    awk -v sc="$SC" '
         /^[^ \t]/ { src = $0; next }                       # non-indented = source port
         index(src, sc ":out_") == 1 && /playback_/ {       # indented hw-playback dest
             dst = $0; sub(/^[ \t]*\|?->? */, "", dst);
@@ -52,11 +61,49 @@ sc_hw_playback_links() {
 # stable rendezvous across controller generations (v2 raw, or v3 translated by
 # lcxl3-driver), which is what keeps the classic LCXL plug-and-play.
 CTRL_IN="ardour:MIDI Control In"
-CTRL_SRC="Midi-Bridge:Midi Through: Port-0 (capture)"
+MASTER_RELINK="${TIDAL_AUTOROUTE_MASTER:-1}"
+MASTER_STATE=""
+
+# The Midi Through capture port, named from the LIVE graph. PipeWire has spelled
+# it two ways ("Midi Through: Port-0 (capture)" and, on 1.0.x,
+# "Midi Through:(capture_0) Midi Through Port-0"); this asserted the first one
+# with errors sent to /dev/null, so on 1.0.5 the assertion was a silent no-op
+# and the faders only worked because Ardour had saved the link itself.
+ctrl_source() {  # stdin: the `pw-link -lo` snapshot
+    awk '/^Midi-Bridge:Midi Through:/ && !/playback/ { print; exit }'
+}
+
+# How many alsa_output sinks Ardour Master reaches.
+master_hw_links() {  # stdin: the `pw-link -lo` snapshot
+    awk '/^[^ \t]/ { src = $0; next }
+         index(src, "ardour:Master/audio_out") == 1 && /alsa_output\./ { n++ }
+         END { print n + 0 }'
+}
+
+# Link Master's two outputs to the first two playback ports of the default sink.
+# Ports are taken from the graph rather than assumed to be FL/FR: an interface
+# names them AUX0/AUX1.
+relink_master() {
+    local sink ports p1 p2
+    sink="$(pactl get-default-sink 2>/dev/null)"
+    [ -n "$sink" ] || return 1
+    ports="$(pw-link -i 2>/dev/null | grep -F "$sink:playback_" | sed -E 's/^[ \t]+//' | sort | head -2)"
+    p1="$(sed -n 1p <<<"$ports")"; p2="$(sed -n 2p <<<"$ports")"
+    [ -n "$p1" ] || return 1
+    link "ardour:Master/audio_out 1" "$p1"
+    [ -n "$p2" ] && link "ardour:Master/audio_out 2" "$p2"
+    return 0
+}
 
 reconcile() {
+    local lo src
+    lo="$(pw-link -lo 2>/dev/null)"           # ONE snapshot per tick, shared below
+
     # ADD: the control surface feed (no-op until Ardour registers the port)
-    link "$CTRL_SRC" "$CTRL_IN"
+    if [[ "$lo" != *"|-> $CTRL_IN"* ]]; then
+        src="$(ctrl_source <<<"$lo")"
+        [ -n "$src" ] && link "$src" "$CTRL_IN"
+    fi
 
     # No Ardour tracks in the graph = not a performance. Route nothing, and
     # above all PRUNE nothing: SC's default sink links are then its ONLY
@@ -68,6 +115,18 @@ reconcile() {
     tracks="$(tidal_track_numbers)"
     [ -n "$tracks" ] || return 0
 
+    # ADD: a hardware output for Master when it has none (additive, see header)
+    if [ "$MASTER_RELINK" = 1 ] && [[ "$lo" == *"ardour:Master/audio_out"* ]] \
+            && [ "$(master_hw_links <<<"$lo")" = 0 ]; then
+        if relink_master; then
+            [ "$MASTER_STATE" = linked ] || echo "tidal-ardour-autoroute: Ardour Master had no hardware output; linked it to the default sink"
+            MASTER_STATE=linked
+        else
+            [ "$MASTER_STATE" = failed ] || echo "tidal-ardour-autoroute: Ardour Master has no hardware output and there is no default sink to give it"
+            MASTER_STATE=failed
+        fi
+    fi
+
     # ADD: orbit pair -> matching Tidal track
     while read -r nn; do
         [ -n "${nn:-}" ] || continue
@@ -81,11 +140,14 @@ reconcile() {
     # playback directly — monitoring is via Ardour Master.
     while IFS=$'\t' read -r src dst; do
         [ -n "${src:-}" ] && [ -n "${dst:-}" ] && pw-link -d "$src" "$dst" 2>/dev/null
-    done < <(sc_hw_playback_links)
+    done < <(sc_hw_playback_links <<<"$lo")
 }
 
-echo "tidal-ardour-autoroute: reconciling orbit->track every ${INTERVAL}s"
-while :; do
-    reconcile
-    sleep "$INTERVAL"
-done
+# Source guard: the tests source this file for its functions.
+if [ "${BASH_SOURCE[0]}" = "$0" ]; then
+    echo "tidal-ardour-autoroute: reconciling orbit->track every ${INTERVAL}s"
+    while :; do
+        reconcile
+        sleep "$INTERVAL"
+    done
+fi