alsa: adjust ucm sink/source priority according to ports priority

On the machines with the ucm used, the different input/output devices
often have different pcm stream, so they often belong to different
sources and sinks, this is greatly different from the design of all
devices connected to a codec (without ucm).

For example, on a machine with ucm2 used:
the internal dmic is on source#0
the external mic is on the source#1
the internal spk is on sink#0
the external headphone is on sink#1

Users expect that after plugging the external device, it will become
the active device automatically. The switch-on-port-available could
make it to be the active_port on its own source/sink, but can't make
source/sink to be default_source/sink since the sources/sinks belong
to the same profile (HiFi usually).

If we adjust the source/sink priority according to ucm ports priority,
the device_port.c could handle the default_source/sink changing then.
Usually we set higher priority for external device than internal
device in the ucm.

In order to bring the lowest side effect on the source/sink priority,
I change the ucm priority to units digit first, then add it to the
original priority.

Signed-off-by: Hui Wang <hui.wang@canonical.com>

src/modules/alsa/alsa-sink.c

@@ -2598,6 +2598,19 @@ pa_sink *pa_alsa_sink_new(pa_module *m, pa_modargs *ma, const char*driver, pa_ca
         goto fail;
     }
 
+    if (u->ucm_context) {
+        pa_device_port *port;
+        void *state;
+        unsigned h_prio = 0;
+        PA_HASHMAP_FOREACH(port, u->sink->ports, state) {
+            if (!h_prio || port->priority > h_prio)
+                h_prio = port->priority;
+        }
+        /* ucm ports prioriy is 100, 200, ..., 900, change it to units digit */
+        h_prio = h_prio / 100;
+        u->sink->priority += h_prio;
+    }
+
     if (pa_modargs_get_value_u32(ma, "deferred_volume_safety_margin",
                                  &u->sink->thread_info.volume_change_safety_margin) < 0) {
         pa_log("Failed to parse deferred_volume_safety_margin parameter");

src/modules/alsa/alsa-source.c

@@ -2284,6 +2284,19 @@ pa_source *pa_alsa_source_new(pa_module *m, pa_modargs *ma, const char*driver, p
         goto fail;
     }
 
+    if (u->ucm_context) {
+        pa_device_port *port;
+        void *state;
+        unsigned h_prio = 0;
+        PA_HASHMAP_FOREACH(port, u->source->ports, state) {
+            if (!h_prio || port->priority > h_prio)
+                h_prio = port->priority;
+        }
+        /* ucm ports prioriy is 100, 200, ..., 900, change it to units digit */
+        h_prio = h_prio / 100;
+        u->source->priority += h_prio;
+    }
+
     if (pa_modargs_get_value_u32(ma, "deferred_volume_safety_margin",
                                  &u->source->thread_info.volume_change_safety_margin) < 0) {
         pa_log("Failed to parse deferred_volume_safety_margin parameter");