module-switch-on-port-available: Route to preferred profile

This makes the routing slightly more aggressive:

 * It will try to route to another profile, if such a profile
   is preferred by the port.

 * It will allow changing profiles on transitions both to
   PA_AVAILABLE_YES and PA_AVAILABLE_NO

To accommodate there is also some refactoring.

Signed-off-by: David Henningsson <david.henningsson@canonical.com>

src/modules/module-switch-on-port-available.c

@@ -74,22 +74,25 @@ static bool profile_good_for_input(pa_card_profile *profile) {
 static int try_to_switch_profile(pa_device_port *port) {
     pa_card_profile *best_profile = NULL, *profile;
     void *state;
+    unsigned best_prio = 0;
 
-    pa_log_debug("Finding best profile");
+    pa_log_debug("Finding best profile for port %s, preferred = %s",
+                 port->name, pa_strnull(port->preferred_profile));
 
     PA_HASHMAP_FOREACH(profile, port->profiles, state) {
         bool good = false;
-
+        const char *name;
-        if (best_profile && best_profile->priority >= profile->priority)
+        unsigned prio = profile->priority;
-            continue;
 
         /* We make a best effort to keep other direction unchanged */
         switch (port->direction) {
             case PA_DIRECTION_OUTPUT:
+                name = profile->output_name;
                 good = profile_good_for_output(profile);
                 break;
 
             case PA_DIRECTION_INPUT:
+                name = profile->input_name;
                 good = profile_good_for_input(profile);
                 break;
         }
@@ -97,7 +100,15 @@ static int try_to_switch_profile(pa_device_port *port) {
         if (!good)
             continue;
 
+        /* Give a high bonus in case this is the preferred profile */
+        if (port->preferred_profile && pa_streq(name ? name : profile->name, port->preferred_profile))
+            prio += 1000000;
+
+        if (best_profile && best_prio >= prio)
+            continue;
+
         best_profile = profile;
+        best_prio = prio;
     }
 
     if (!best_profile) {
@@ -113,98 +124,125 @@ static int try_to_switch_profile(pa_device_port *port) {
     return 0;
 }
 
-static void find_sink_and_source(pa_card *card, pa_device_port *port, pa_sink **si, pa_source **so) {
+struct port_pointers {
-    pa_sink *sink = NULL;
+    pa_device_port *port;
-    pa_source *source = NULL;
+    pa_sink *sink;
+    pa_source *source;
+    bool is_possible_profile_active;
+    bool is_preferred_profile_active;
+    bool is_port_active;
+};
+
+static const char* profile_name_for_dir(pa_card_profile *cp, pa_direction_t dir) {
+    if (dir == PA_DIRECTION_OUTPUT && cp->output_name)
+        return cp->output_name;
+    if (dir == PA_DIRECTION_INPUT && cp->input_name)
+        return cp->input_name;
+    return cp->name;
+}
+
+static struct port_pointers find_port_pointers(pa_device_port *port) {
+    struct port_pointers pp = { .port = port };
     uint32_t state;
+    pa_card *card;
+
+    pa_assert(port);
+    pa_assert_se(card = port->card);
 
     switch (port->direction) {
         case PA_DIRECTION_OUTPUT:
-            PA_IDXSET_FOREACH(sink, card->sinks, state)
+            PA_IDXSET_FOREACH(pp.sink, card->sinks, state)
-                if (port == pa_hashmap_get(sink->ports, port->name))
+                if (port == pa_hashmap_get(pp.sink->ports, port->name))
                     break;
             break;
 
         case PA_DIRECTION_INPUT:
-            PA_IDXSET_FOREACH(source, card->sources, state)
+            PA_IDXSET_FOREACH(pp.source, card->sources, state)
-                if (port == pa_hashmap_get(source->ports, port->name))
+                if (port == pa_hashmap_get(pp.source->ports, port->name))
                     break;
             break;
     }
 
-    *si = sink;
+    pp.is_possible_profile_active =
-    *so = source;
+        card->active_profile == pa_hashmap_get(port->profiles, card->active_profile->name);
+    pp.is_preferred_profile_active = pp.is_possible_profile_active && (!port->preferred_profile ||
+        pa_safe_streq(port->preferred_profile, profile_name_for_dir(card->active_profile, port->direction)));
+    pp.is_port_active = (pp.sink && pp.sink->active_port == port) || (pp.source && pp.source->active_port == port);
+
+    return pp;
 }
 
+/* Switches to a port, switching profiles if necessary or preferred */
+static bool switch_to_port(pa_device_port *port) {
+    struct port_pointers pp = find_port_pointers(port);
+
+    if (pp.is_port_active)
+        return true; /* Already selected */
+
+    pa_log_debug("Trying to switch to port %s", port->name);
+    if (!pp.is_preferred_profile_active) {
+        if (try_to_switch_profile(port) < 0) {
+            if (pp.is_possible_profile_active)
+                return false;
+        }
+        else
+            /* Now that profile has changed, our sink and source pointers must be updated */
+            pp = find_port_pointers(port);
+    }
+
+    if (pp.source)
+        pa_source_set_port(pp.source, port->name, false);
+    if (pp.sink)
+        pa_sink_set_port(pp.sink, port->name, false);
+    return true;
+}
+
+/* Switches away from a port, switching profiles if necessary or preferred */
+static bool switch_from_port(pa_device_port *port) {
+    struct port_pointers pp = find_port_pointers(port);
+    pa_device_port *p, *best_port = NULL;
+    void *state;
+
+    if (!pp.is_port_active)
+        return true; /* Already deselected */
+
+    /* Try to find a good enough port to switch to */
+    PA_HASHMAP_FOREACH(p, port->card->ports, state)
+        if (p->direction == port->direction && p != port && p->available != PA_AVAILABLE_NO &&
+           (!best_port || best_port->priority < p->priority))
+           best_port = p;
+
+    pa_log_debug("Trying to switch away from port %s, found %s", port->name, best_port ? best_port->name : "no better option");
+
+    if (best_port)
+        return switch_to_port(best_port);
+
+    return false;
+}
+
+
 static pa_hook_result_t port_available_hook_callback(pa_core *c, pa_device_port *port, void* userdata) {
-    pa_card* card;
+    pa_assert(port);
-    pa_sink *sink;
-    pa_source *source;
-    bool is_active_profile, is_active_port;
 
-    if (port->available == PA_AVAILABLE_UNKNOWN)
+    if (!port->card) {
-        return PA_HOOK_OK;
-
-    card = port->card;
-
-    if (!card) {
         pa_log_warn("Port %s does not have a card", port->name);
         return PA_HOOK_OK;
     }
 
-    if (pa_idxset_size(card->sinks) == 0 && pa_idxset_size(card->sources) == 0)
+    if (pa_idxset_size(port->card->sinks) == 0 && pa_idxset_size(port->card->sources) == 0)
         /* This card is not initialized yet. We'll handle it in
            sink_new / source_new callbacks later. */
         return PA_HOOK_OK;
 
-    find_sink_and_source(card, port, &sink, &source);
+    switch (port->available) {
-
+    case PA_AVAILABLE_YES:
-    is_active_profile = card->active_profile == pa_hashmap_get(port->profiles, card->active_profile->name);
+        switch_to_port(port);
-    is_active_port = (sink && sink->active_port == port) || (source && source->active_port == port);
+        break;
-
+    case PA_AVAILABLE_NO:
-    if (port->available == PA_AVAILABLE_NO && !is_active_port)
+        switch_from_port(port);
-        return PA_HOOK_OK;
+        break;
-
+    default:
-    if (port->available == PA_AVAILABLE_YES) {
+        break;
-        if (is_active_port)
-            return PA_HOOK_OK;
-
-        if (!is_active_profile) {
-            if (try_to_switch_profile(port) < 0)
-                return PA_HOOK_OK;
-
-            pa_assert(card->active_profile == pa_hashmap_get(port->profiles, card->active_profile->name));
-
-            /* Now that profile has changed, our sink and source pointers must be updated */
-            find_sink_and_source(card, port, &sink, &source);
-        }
-
-        if (source)
-            pa_source_set_port(source, port->name, false);
-        if (sink)
-            pa_sink_set_port(sink, port->name, false);
-    }
-
-    if (port->available == PA_AVAILABLE_NO) {
-        if (sink) {
-            pa_device_port *p2 = pa_device_port_find_best(sink->ports);
-
-            if (p2 && p2->available != PA_AVAILABLE_NO)
-                pa_sink_set_port(sink, p2->name, false);
-            else {
-                /* Maybe try to switch to another profile? */
-            }
-        }
-
-        if (source) {
-            pa_device_port *p2 = pa_device_port_find_best(source->ports);
-
-            if (p2 && p2->available != PA_AVAILABLE_NO)
-                pa_source_set_port(source, p2->name, false);
-            else {
-                /* Maybe try to switch to another profile? */
-            }
-        }
     }
 
     return PA_HOOK_OK;