staging: greybus: loopback.c: remove unused lists

gb_loopback_device::list_op_async is never used except for the
LIST_INIT. The ::list field appears to have a few more uses, but on
closer inspection the linked list of struct gb_loopbacks that it heads
is never used for anything, so there's no reason to maintain it, much
less to keep it sorted.
Reviewed-by: Bryan O'Donoghue <pure.logic@nexus-software.ie>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/greybus/loopback.c

@@ -47,8 +47,6 @@ struct gb_loopback_device {
 
 	/* We need to take a lock in atomic context */
 	spinlock_t lock;
-	struct list_head list;
-	struct list_head list_op_async;
 	wait_queue_head_t wq;
 };
 
@@ -68,7 +66,6 @@ struct gb_loopback {
 	struct kfifo kfifo_lat;
 	struct mutex mutex;
 	struct task_struct *task;
-	struct list_head entry;
 	struct device *dev;
 	wait_queue_head_t wq;
 	wait_queue_head_t wq_completion;
@@ -987,37 +984,6 @@ static const struct file_operations gb_loopback_debugfs_latency_ops = {
 	.release	= single_release,
 };
 
-static int gb_loopback_bus_id_compare(void *priv, struct list_head *lha,
-				      struct list_head *lhb)
-{
-	struct gb_loopback *a = list_entry(lha, struct gb_loopback, entry);
-	struct gb_loopback *b = list_entry(lhb, struct gb_loopback, entry);
-	struct gb_connection *ca = a->connection;
-	struct gb_connection *cb = b->connection;
-
-	if (ca->bundle->intf->interface_id < cb->bundle->intf->interface_id)
-		return -1;
-	if (cb->bundle->intf->interface_id < ca->bundle->intf->interface_id)
-		return 1;
-	if (ca->bundle->id < cb->bundle->id)
-		return -1;
-	if (cb->bundle->id < ca->bundle->id)
-		return 1;
-	if (ca->intf_cport_id < cb->intf_cport_id)
-		return -1;
-	else if (cb->intf_cport_id < ca->intf_cport_id)
-		return 1;
-
-	return 0;
-}
-
-static void gb_loopback_insert_id(struct gb_loopback *gb)
-{
-	/* perform an insertion sort */
-	list_add_tail(&gb->entry, &gb_dev.list);
-	list_sort(NULL, &gb_dev.list, gb_loopback_bus_id_compare);
-}
-
 #define DEBUGFS_NAMELEN 32
 
 static int gb_loopback_probe(struct gb_bundle *bundle,
@@ -1113,7 +1079,6 @@ static int gb_loopback_probe(struct gb_bundle *bundle,
 	}
 
 	spin_lock_irqsave(&gb_dev.lock, flags);
-	gb_loopback_insert_id(gb);
 	gb_dev.count++;
 	spin_unlock_irqrestore(&gb_dev.lock, flags);
 
@@ -1169,7 +1134,6 @@ static void gb_loopback_disconnect(struct gb_bundle *bundle)
 
 	spin_lock_irqsave(&gb_dev.lock, flags);
 	gb_dev.count--;
-	list_del(&gb->entry);
 	spin_unlock_irqrestore(&gb_dev.lock, flags);
 
 	device_unregister(gb->dev);
@@ -1196,8 +1160,6 @@ static int loopback_init(void)
 {
 	int retval;
 
-	INIT_LIST_HEAD(&gb_dev.list);
-	INIT_LIST_HEAD(&gb_dev.list_op_async);
 	spin_lock_init(&gb_dev.lock);
 	gb_dev.root = debugfs_create_dir("gb_loopback", NULL);