greybus: audio_manager: use an 'ida' for the module id

Every time we hotplug an audio module, we get a new audio module id.  We
should recycle them instead of just constantly incrementing the number
so we don't see things like:
	[178016.832580] Created audio module #6124
in the kernel logs.

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

diff --git a/drivers/staging/greybus/audio_manager.c b/drivers/staging/greybus/audio_manager.c
index 1176763..05af441 100644 (file)
--- a/drivers/staging/greybus/audio_manager.c
+++ b/drivers/staging/greybus/audio_manager.c
@@ -19,8 +19,7 @@ static struct kset *manager_kset;
 
 static LIST_HEAD(modules_list);
 static DEFINE_RWLOCK(modules_lock);
-
-static int current_module_id;
+static DEFINE_IDA(module_id);
 
 /* helpers */
 static struct gb_audio_manager_module *gb_audio_manager_get_locked(int id)
@@ -43,12 +42,16 @@ int gb_audio_manager_add(struct gb_audio_manager_module_descriptor *desc)
 {
        struct gb_audio_manager_module *module;
        unsigned long flags;
+       int id;
        int err;
 
+       id = ida_simple_get(&module_id, 0, 0, GFP_KERNEL);
        err = gb_audio_manager_module_create(&module, manager_kset,
-                                            current_module_id++, desc);
-       if (err)
+                                            id, desc);
+       if (err) {
+               ida_simple_remove(&module_id, id);
                return err;
+       }
 
        /* Add it to the list */
        write_lock_irqsave(&modules_lock, flags);
@@ -72,6 +75,7 @@ int gb_audio_manager_remove(int id)
                return -EINVAL;
        }
 
+       ida_simple_remove(&module_id, module->id);
        list_del(&module->list);
        kobject_put(&module->kobj);
        write_unlock_irqrestore(&modules_lock, flags);
@@ -175,6 +179,7 @@ static void __exit manager_exit(void)
 {
        gb_audio_manager_remove_all();
        kset_unregister(manager_kset);
+       ida_destroy(&module_id);
 }
 
 module_init(manager_init);