[Bluetooth] Add module parameter for disabling ISOC transfers

Some USB host controllers don't like the way Bluetooth USB dongles uses
the isochronous transfers for the SCO audio support. This patch makes it
possible to disable them without recompiling the driver.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

drivers/bluetooth/hci_usb.c

@@ -40,6 +40,7 @@
 #include <linux/unistd.h>
 #include <linux/types.h>
 #include <linux/interrupt.h>
+#include <linux/moduleparam.h>
 
 #include <linux/slab.h>
 #include <linux/errno.h>
@@ -65,6 +66,10 @@
 #define URB_ZERO_PACKET 0
 #endif
 
+#ifdef CONFIG_BT_HCIUSB_SCO
+static int isoc = 1;
+#endif
+
 #define VERSION "2.7"
 
 static struct usb_driver hci_usb_driver; 
@@ -867,7 +872,7 @@ int hci_usb_probe(struct usb_interface *intf, const struct usb_device_id *id)
 	isoc_ifnum = 1;
 
 #ifdef CONFIG_BT_HCIUSB_SCO
-	if (!(id->driver_info & HCI_BROKEN_ISOC))
+	if (isoc && !(id->driver_info & HCI_BROKEN_ISOC))
 		isoc_iface = usb_ifnum_to_if(udev, isoc_ifnum);
 
 	if (isoc_iface) {
@@ -1018,6 +1023,11 @@ static void __exit hci_usb_exit(void)
 module_init(hci_usb_init);
 module_exit(hci_usb_exit);
 
+#ifdef CONFIG_BT_HCIUSB_SCO
+module_param(isoc, bool, 0);
+MODULE_PARM_DESC(isoc, "Set isochronous transfers for SCO over HCI support");
+#endif
+
 MODULE_AUTHOR("Maxim Krasnyansky <maxk@qualcomm.com>, Marcel Holtmann <marcel@holtmann.org>");
 MODULE_DESCRIPTION("Bluetooth HCI USB driver ver " VERSION);
 MODULE_VERSION(VERSION);