module-bluetooth-policy: Remember last used profile.

When switching profile to HSP due to the auto_switch parameter
being set, make module-bluetooth-policy remember the current profile
in use by the card. In this way, when the reverting to the original
profile, the card won't fallback to the default A2DP profile, but
will go back to whatever profile was being used at the time of switching
(e.g. LDAC).

src/modules/bluetooth/module-bluetooth-policy.c

@@ -63,7 +63,8 @@ struct userdata {
     pa_hook_slot *card_init_profile_slot;
     pa_hook_slot *card_unlink_slot;
     pa_hook_slot *profile_available_changed_slot;
-    pa_hashmap *will_need_revert_card_map;
+    /** Map between cards and their previous profile. */
+    pa_hashmap *old_profile_card_map;
 };
 
 /* When a source is created, loopback it to default sink */
@@ -146,19 +147,24 @@ static pa_hook_result_t sink_put_hook_callback(pa_core *c, pa_sink *sink, void *
     return PA_HOOK_OK;
 }
 
-static void card_set_profile(struct userdata *u, pa_card *card, bool revert_to_a2dp)
+static void card_set_profile(struct userdata *u, pa_card *card, bool revert_to_a2dp, const char* new_profile)
 {
     pa_card_profile *profile;
     void *state;
 
+    /* The revert_to_a2dp and profile parameter are mutually exclusive. */
+    pa_assert(revert_to_a2dp != (!new_profile));
+    char* current_profile = pa_xstrdup(card->active_profile->name);
+    bool switched = false;
+
     /* Find available profile and activate it */
     PA_HASHMAP_FOREACH(profile, card->profiles, state) {
         if (profile->available == PA_AVAILABLE_NO)
             continue;
 
         /* Check for correct profile based on revert_to_a2dp */
         if (revert_to_a2dp) {
-            if (!pa_streq(profile->name, "a2dp") && !pa_bt_prefix_eq(profile->name, "a2dp_sink"))
+            if (!pa_streq(profile->name, new_profile))
                 continue;
         } else {
             if (!pa_streq(profile->name, "hsp") && !pa_streq(profile->name, "headset_head_unit"))
@@ -171,48 +177,58 @@ static void card_set_profile(struct userdata *u, pa_card *card, bool revert_to_a
             pa_log_warn("Could not set profile '%s'", profile->name);
             continue;
         }
-
-        /* When we are not in revert_to_a2dp phase flag this card for will_need_revert */
-        if (!revert_to_a2dp)
-            pa_hashmap_put(u->will_need_revert_card_map, card, PA_INT_TO_PTR(1));
-
+        switched = true;
         break;
     }
+    /*
+     * When we are not in revert_to_a2dp phase flag that this card will need a revert.
+     * Save the old profile.
+     */
+    if (switched && !revert_to_a2dp) {
+        pa_hashmap_put(u->old_profile_card_map, card, current_profile);
+    } else {
+        free(current_profile);
+    }
 }
 
 /* Switch profile for one card */
 static void switch_profile(pa_card *card, bool revert_to_a2dp, void *userdata) {
     struct userdata *u = userdata;
     const char *s;
+    const char *old_profile = NULL;
 
     /* Only consider bluetooth cards */
     s = pa_proplist_gets(card->proplist, PA_PROP_DEVICE_BUS);
     if (!s || !pa_streq(s, "bluetooth"))
         return;
 
     if (revert_to_a2dp) {
-        /* In revert_to_a2dp phase only consider cards with will_need_revert flag and remove it */
-        if (!pa_hashmap_remove(u->will_need_revert_card_map, card))
-            return;
+        /* In revert_to_a2dp phase only consider cards with an old profile stored and remove it. */
+        if (!(old_profile = pa_hashmap_get(u->old_profile_card_map, card)))
+            goto fail;
 
         /* Skip card if does not have active hsp profile */
         if (!pa_streq(card->active_profile->name, "hsp") && !pa_streq(card->active_profile->name, "headset_head_unit"))
-            return;
+            goto fail;
 
         /* Skip card if already has active a2dp profile */
         if (pa_streq(card->active_profile->name, "a2dp") || pa_strneq(card->active_profile->name, "a2dp_sink", strlen("a2dp_sink")))
-            return;
+            goto fail;
     } else {
         /* Skip card if does not have active a2dp profile */
         if (!pa_streq(card->active_profile->name, "a2dp") && !pa_bt_prefix_eq(card->active_profile->name, "a2dp_sink"))
-            return;
+            goto fail;
 
         /* Skip card if already has active hsp profile */
         if (pa_streq(card->active_profile->name, "hsp") || pa_streq(card->active_profile->name, "headset_head_unit"))
-            return;
+            goto fail;
     }
 
-    card_set_profile(u, card, revert_to_a2dp);
+    card_set_profile(u, card, revert_to_a2dp, old_profile);
+fail:
+    if (revert_to_a2dp) {
+        pa_hashmap_remove_and_free(u->old_profile_card_map, card);
+    }
 }
 
 /* Return true if we should ignore this source output */
@@ -316,10 +332,7 @@ static pa_hook_result_t card_init_profile_hook_callback(pa_core *c, pa_card *car
         return PA_HOOK_OK;
 
     /* Set initial profile to hsp */
-    card_set_profile(u, card, false);
-
-    /* Flag this card for will_need_revert */
-    pa_hashmap_put(u->will_need_revert_card_map, card, PA_INT_TO_PTR(1));
+    card_set_profile(u, card, false, NULL);
     return PA_HOOK_OK;
 }
 
@@ -452,7 +465,7 @@ int pa__init(pa_module *m) {
         goto fail;
     }
 
-    u->will_need_revert_card_map = pa_hashmap_new(pa_idxset_trivial_hash_func, pa_idxset_trivial_compare_func);
+    u->old_profile_card_map = pa_hashmap_new(pa_idxset_trivial_hash_func, pa_idxset_trivial_compare_func);
 
     u->source_put_slot = pa_hook_connect(&m->core->hooks[PA_CORE_HOOK_SOURCE_PUT], PA_HOOK_NORMAL,
                                          (pa_hook_cb_t) source_put_hook_callback, u);
@@ -517,7 +530,7 @@ void pa__done(pa_module *m) {
     if (u->profile_available_changed_slot)
         pa_hook_slot_free(u->profile_available_changed_slot);
 
-    pa_hashmap_free(u->will_need_revert_card_map);
+    pa_hashmap_free(u->old_profile_card_map);
 
     pa_xfree(u);
 }