usb: core: allow isoc URBs for wireless devices with an interval < 6

In usb_submit_urb, do not fail if an isoc URB for a wireless USB device
has an interval < 6.  Per WUSB spec, isoc endpoints can support values
from 1-16.  Valid values for interrupt URBs for wireless USB devices are
still 6-16.

Signed-off-by: Thomas Pugliese <thomas.pugliese@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/core/urb.c

@@ -492,9 +492,9 @@ int usb_submit_urb(struct urb *urb, gfp_t mem_flags)
 		/* too small? */
 		switch (dev->speed) {
 		case USB_SPEED_WIRELESS:
-			if (urb->interval < 6)
+			if ((urb->interval < 6)
+				&& (xfertype == USB_ENDPOINT_XFER_INT))
 				return -EINVAL;
-			break;
 		default:
 			if (urb->interval <= 0)
 				return -EINVAL;