[BlueZ] mesh: Update the behavior of --io option

diff --git a/mesh/bluetooth-meshd.rst.in b/mesh/bluetooth-meshd.rst.in
index 06cdb69da..761536711 100644
--- a/mesh/bluetooth-meshd.rst.in
+++ b/mesh/bluetooth-meshd.rst.in
@@ -36,14 +36,17 @@  OPTIONS
 -i <type>, --io <type>
     Specifies I/O interface type:
 
-    *hci<index>* - Use generic HCI io on interface hci<index>,
-    or, if no idex is specified, the first available one.
+    *auto* - Use first available controller: via MGMT interface
+    if kernel supports it, otherwise, via raw HCI socket.
+
+    *generic:[hci]<index>* - Use generic HCI io on interface
+    hci<index>.
 
     *unit:<fd_path>*- Specifies open file descriptor for
     daemon testing.
 
-    By default, if no type is specified, uses generic I/O
-    on the first available HCI interface.
+    By default, if no type is specified, uses auto I/O
+    on the first available controller.
 
 -c <file>, --config <file>
     Specifies an explicit config file path instead of relying on the
diff --git a/mesh/main.c b/mesh/main.c
index 3bca020a0..145bcfa98 100644
--- a/mesh/main.c
+++ b/mesh/main.c
@@ -48,6 +48,12 @@  static const struct option main_options[] = {
 	{ }
 };
 
+static const char *io_usage =
+	       "\t(auto | generic:[hci]<index> | unit:<fd_path>)\n"
+	       "\t\tauto - Use first available controller (MGMT or raw HCI)\n"
+	       "\t\tgeneric - Use raw HCI io on interface hci<index>\n"
+	       "\t\tunit - Use test IO (for automatic testing only)\n";
+
 static void usage(void)
 {
 	fprintf(stderr,
@@ -55,18 +61,14 @@  static void usage(void)
 	       "\tbluetooth-meshd [options]\n");
 	fprintf(stderr,
 		"Options:\n"
-	       "\t--io <io>         Use specified io (default: generic)\n"
+	       "\t--io <io>         Use specified io (default: auto)\n"
 	       "\t--config          Daemon configuration directory\n"
 	       "\t--storage         Mesh node(s) configuration directory\n"
 	       "\t--nodetach        Run in foreground\n"
 	       "\t--debug           Enable debug output\n"
 	       "\t--dbus-debug      Enable D-Bus debugging\n"
 	       "\t--help            Show %s information\n", __func__);
-	fprintf(stderr,
-	       "io:\n"
-	       "\t([hci]<index> | generic[:[hci]<index>] | unit:<fd_path>)\n"
-	       "\t\tUse generic HCI io on interface hci<index>, or the first\n"
-	       "\t\tavailable one\n");
+	fprintf(stderr, "\n\t io: %s", io_usage);
 }
 
 static void do_debug(const char *str, void *user_data)
@@ -157,21 +159,8 @@  static bool parse_io(const char *optarg, enum mesh_io_type *type, void **opts)
 		*opts = index;
 
 		optarg += strlen("auto");
-		if (!*optarg) {
-			*index = MGMT_INDEX_NONE;
-			return true;
-		}
-
-		if (*optarg != ':')
-			return false;
-
-		optarg++;
-
-		if (sscanf(optarg, "hci%d", index) == 1)
-			return true;
-
-		if (sscanf(optarg, "%d", index) == 1)
-			return true;
+		*index = MGMT_INDEX_NONE;
+		return true;
 
 		return false;
 	} else if (strstr(optarg, "generic") == optarg) {
@@ -181,12 +170,7 @@  static bool parse_io(const char *optarg, enum mesh_io_type *type, void **opts)
 		*opts = index;
 
 		optarg += strlen("generic");
-		if (!*optarg) {
-			*index = MGMT_INDEX_NONE;
-			return true;
-		}
-
-		if (*optarg != ':')
+		if (!*optarg || *optarg != ':')
 			return false;
 
 		optarg++;
@@ -291,7 +275,7 @@  int main(int argc, char *argv[])
 		io = l_strdup_printf("auto");
 
 	if (!parse_io(io, &io_type, &io_opts)) {
-		l_error("Invalid io: %s", io);
+		l_error("Invalid io: %s\n%s", io, io_usage);
 		status = EXIT_FAILURE;
 		goto done;
 	}
diff --git a/mesh/mesh-io-generic.c b/mesh/mesh-io-generic.c
index 93a56275b..00932ade7 100644
--- a/mesh/mesh-io-generic.c
+++ b/mesh/mesh-io-generic.c
@@ -380,6 +380,9 @@  static void hci_init(void *user_data)
 	if (io->pvt->hci)
 		bt_hci_unref(io->pvt->hci);
 
+	/* Clear controller HCI list to suppress mgmt interface warnings */
+	mesh_mgmt_clear();
+
 	io->pvt->hci = bt_hci_new_user_channel(io->index);
 	if (!io->pvt->hci) {
 		l_error("Failed to start mesh io (hci %u): %s", io->index,
diff --git a/mesh/mesh-io.c b/mesh/mesh-io.c
index 48e3f4226..b953bf4cf 100644
--- a/mesh/mesh-io.c
+++ b/mesh/mesh-io.c
@@ -72,12 +72,20 @@  static void ctl_alert(int index, bool up, bool pwr, bool mesh, void *user_data)
 	enum mesh_io_type type = L_PTR_TO_UINT(user_data);
 	const struct mesh_io_api *api = NULL;
 
-	l_warn("up:%d pwr: %d mesh: %d", up, pwr, mesh);
+	l_warn("index %u up:%d pwr: %d mesh: %d", index, up, pwr, mesh);
 
 	/* If specific IO controller requested, honor it */
-	if (default_io->favored_index != MGMT_INDEX_NONE &&
-					default_io->favored_index != index)
-		return;
+	if (default_io->favored_index != MGMT_INDEX_NONE) {
+		if (default_io->favored_index != index)
+			return;
+
+		if (!up | pwr) {
+			l_warn("HCI%u failed to start generic IO %s",
+				index, pwr ? ": already powered on" : "");
+			if (default_io->ready)
+				default_io->ready(default_io->user_data, false);
+		}
+	}
 
 	if (!up && default_io->index == index) {
 		/* Our controller has disappeared */
@@ -104,7 +112,6 @@  static void ctl_alert(int index, bool up, bool pwr, bool mesh, void *user_data)
 		default_io->index = index;
 		default_io->api = api;
 		api->init(default_io, &index, default_io->user_data);
-
 		l_queue_foreach(default_io->rx_regs, refresh_rx, default_io);
 	}
 }
diff --git a/mesh/mesh-mgmt.c b/mesh/mesh-mgmt.c
index d37aeb5ac..fd21a168a 100644
--- a/mesh/mesh-mgmt.c
+++ b/mesh/mesh-mgmt.c
@@ -271,3 +271,8 @@  bool mesh_mgmt_unregister(unsigned int id)
 {
 	return mgmt_unregister(mgmt_mesh, id);
 }
+
+void mesh_mgmt_clear(void)
+{
+	l_queue_clear(ctl_list, l_free);
+}
diff --git a/mesh/mesh-mgmt.h b/mesh/mesh-mgmt.h
index a3cd72faf..570282297 100644
--- a/mesh/mesh-mgmt.h
+++ b/mesh/mesh-mgmt.h
@@ -22,3 +22,4 @@  unsigned int mesh_mgmt_register(uint16_t event, uint16_t index,
 				void *user_data, mgmt_destroy_func_t destroy);
 bool mesh_mgmt_unregister(unsigned int id);
 void mesh_mgmt_destroy(void);
+void mesh_mgmt_clear(void);