usb-core: Free bulk streams on interface release

Documentation/usb/bulk-streams.txt says:

All stream IDs will be deallocated when the driver releases the interface, to
ensure that drivers that don't support streams will be able to use the endpoint

This commit actually implements this.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>

drivers/usb/core/driver.c

@@ -400,8 +400,9 @@ static int usb_unbind_interface(struct device *dev)
 {
 	struct usb_driver *driver = to_usb_driver(dev->driver);
 	struct usb_interface *intf = to_usb_interface(dev);
+	struct usb_host_endpoint *ep, **eps = NULL;
 	struct usb_device *udev;
-	int error, r, lpm_disable_error;
+	int i, j, error, r, lpm_disable_error;
 
 	intf->condition = USB_INTERFACE_UNBINDING;
 
@@ -425,6 +426,26 @@ static int usb_unbind_interface(struct device *dev)
 	driver->disconnect(intf);
 	usb_cancel_queued_reset(intf);
 
+	/* Free streams */
+	for (i = 0, j = 0; i < intf->cur_altsetting->desc.bNumEndpoints; i++) {
+		ep = &intf->cur_altsetting->endpoint[i];
+		if (ep->streams == 0)
+			continue;
+		if (j == 0) {
+			eps = kmalloc(USB_MAXENDPOINTS * sizeof(void *),
+				      GFP_KERNEL);
+			if (!eps) {
+				dev_warn(dev, "oom, leaking streams\n");
+				break;
+			}
+		}
+		eps[j++] = ep;
+	}
+	if (j) {
+		usb_free_streams(intf, eps, j, GFP_KERNEL);
+		kfree(eps);
+	}
+
 	/* Reset other interface state.
 	 * We cannot do a Set-Interface if the device is suspended or
 	 * if it is prepared for a system sleep (since installing a new