USB: Add support for SuperSpeed isoc endpoints
Use the Mult and bMaxBurst values from the endpoint companion
descriptor to calculate the max length of an isoc transfer.
Add USB_SS_MULT macro to access Mult field of bmAttributes, at
Sarah's suggestion.
This patch should be queued for the 2.6.36 and 2.6.37 stable trees, since
those were the first kernels to have isochronous support for SuperSpeed
devices.
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@kernel.org
diff --git a/drivers/usb/core/urb.c b/drivers/usb/core/urb.c
index c14fc082..ae334b0 100644
--- a/drivers/usb/core/urb.c
+++ b/drivers/usb/core/urb.c
@@ -366,7 +366,16 @@
if (xfertype == USB_ENDPOINT_XFER_ISOC) {
int n, len;
- /* FIXME SuperSpeed isoc endpoints have up to 16 bursts */
+ /* SuperSpeed isoc endpoints have up to 16 bursts of up to
+ * 3 packets each
+ */
+ if (dev->speed == USB_SPEED_SUPER) {
+ int burst = 1 + ep->ss_ep_comp.bMaxBurst;
+ int mult = USB_SS_MULT(ep->ss_ep_comp.bmAttributes);
+ max *= burst;
+ max *= mult;
+ }
+
/* "high bandwidth" mode, 1-3 packets/uframe? */
if (dev->speed == USB_SPEED_HIGH) {
int mult = 1 + ((max >> 11) & 0x03);