Bluetooth: Create per controller workqueue

Instead of having a global workqueue for all controllers, it makes
more sense to have a workqueue per controller.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

net/bluetooth/hci_core.c

@@ -37,6 +37,7 @@
 #include <linux/fcntl.h>
 #include <linux/init.h>
 #include <linux/skbuff.h>
+#include <linux/workqueue.h>
 #include <linux/interrupt.h>
 #include <linux/notifier.h>
 #include <linux/rfkill.h>
@@ -928,6 +929,10 @@ int hci_register_dev(struct hci_dev *hdev)
 
 	write_unlock_bh(&hci_dev_list_lock);
 
+	hdev->workqueue = create_singlethread_workqueue(hdev->name);
+	if (!hdev->workqueue)
+		goto nomem;
+
 	hci_register_sysfs(hdev);
 
 	hdev->rfkill = rfkill_alloc(hdev->name, &hdev->dev,
@@ -942,6 +947,13 @@ int hci_register_dev(struct hci_dev *hdev)
 	hci_notify(hdev, HCI_DEV_REG);
 
 	return id;
+
+nomem:
+	write_lock_bh(&hci_dev_list_lock);
+	list_del(&hdev->list);
+	write_unlock_bh(&hci_dev_list_lock);
+
+	return -ENOMEM;
 }
 EXPORT_SYMBOL(hci_register_dev);
 
@@ -970,6 +982,8 @@ int hci_unregister_dev(struct hci_dev *hdev)
 
 	hci_unregister_sysfs(hdev);
 
+	destroy_workqueue(hdev->workqueue);
+
 	__hci_dev_put(hdev);
 
 	return 0;