[PATCH] USB: hid intervals

I noticed the HID driver had some potential misbehavior ...


Bugfix handling for HID devices at high speed (interrupt interval encoding
is log2 not linear), and for interrupt OUT transfers (use the interval
the hardware actually supports).
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

drivers/usb/input/hid-core.c

@@ -1619,11 +1619,17 @@ static struct hid_device *usb_hid_configure(struct usb_interface *intf)
 
 		struct usb_endpoint_descriptor *endpoint;
 		int pipe;
+		int interval;
 
 		endpoint = &interface->endpoint[n].desc;
 		if ((endpoint->bmAttributes & 3) != 3)		/* Not an interrupt endpoint */
 			continue;
 
+		/* handle potential highspeed HID correctly */
+		interval = endpoint->bInterval;
+		if (dev->speed == USB_SPEED_HIGH)
+			interval = 1 << (interval - 1);
+
 		if (endpoint->bEndpointAddress & USB_DIR_IN) {
 			int len;
 
@@ -1636,7 +1642,7 @@ static struct hid_device *usb_hid_configure(struct usb_interface *intf)
 			if (len > HID_BUFFER_SIZE)
 				len = HID_BUFFER_SIZE;
 			usb_fill_int_urb(hid->urbin, dev, pipe, hid->inbuf, len,
-					 hid_irq_in, hid, endpoint->bInterval);
+					 hid_irq_in, hid, interval);
 			hid->urbin->transfer_dma = hid->inbuf_dma;
 			hid->urbin->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 		} else {
@@ -1646,7 +1652,7 @@ static struct hid_device *usb_hid_configure(struct usb_interface *intf)
 				goto fail;
 			pipe = usb_sndintpipe(dev, endpoint->bEndpointAddress);
 			usb_fill_int_urb(hid->urbout, dev, pipe, hid->outbuf, 0,
-					  hid_irq_out, hid, 1);
+					 hid_irq_out, hid, interval);
 			hid->urbout->transfer_dma = hid->outbuf_dma;
 			hid->urbout->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 		}