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-rw-r--r--include/linux/usb.h18
1 files changed, 13 insertions, 5 deletions
diff --git a/include/linux/usb.h b/include/linux/usb.h
index 8c9f053111b..ce1323c4e47 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -1055,7 +1055,8 @@ typedef void (*usb_complete_t)(struct urb *);
* @number_of_packets: Lists the number of ISO transfer buffers.
* @interval: Specifies the polling interval for interrupt or isochronous
* transfers. The units are frames (milliseconds) for full and low
- * speed devices, and microframes (1/8 millisecond) for highspeed ones.
+ * speed devices, and microframes (1/8 millisecond) for highspeed
+ * and SuperSpeed devices.
* @error_count: Returns the number of ISO transfers that reported errors.
* @context: For use in completion functions. This normally points to
* request-specific driver context.
@@ -1286,9 +1287,16 @@ static inline void usb_fill_bulk_urb(struct urb *urb,
*
* Initializes a interrupt urb with the proper information needed to submit
* it to a device.
- * Note that high speed interrupt endpoints use a logarithmic encoding of
- * the endpoint interval, and express polling intervals in microframes
- * (eight per millisecond) rather than in frames (one per millisecond).
+ *
+ * Note that High Speed and SuperSpeed interrupt endpoints use a logarithmic
+ * encoding of the endpoint interval, and express polling intervals in
+ * microframes (eight per millisecond) rather than in frames (one per
+ * millisecond).
+ *
+ * Wireless USB also uses the logarithmic encoding, but specifies it in units of
+ * 128us instead of 125us. For Wireless USB devices, the interval is passed
+ * through to the host controller, rather than being translated into microframe
+ * units.
*/
static inline void usb_fill_int_urb(struct urb *urb,
struct usb_device *dev,
@@ -1305,7 +1313,7 @@ static inline void usb_fill_int_urb(struct urb *urb,
urb->transfer_buffer_length = buffer_length;
urb->complete = complete_fn;
urb->context = context;
- if (dev->speed == USB_SPEED_HIGH)
+ if (dev->speed == USB_SPEED_HIGH || dev->speed == USB_SPEED_SUPER)
urb->interval = 1 << (interval - 1);
else
urb->interval = interval;