This is a note to let you know that I've just added the patch titled
USB: Add support for SuperSpeed isoc endpoints
to the 2.6.37-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
usb-add-support-for-superspeed-isoc-endpoints.patch
and it can be found in the queue-2.6.37 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 500132a0f26ad7d9916102193cbc6c1b1becb373 Mon Sep 17 00:00:00 2001
From: Paul Zimmerman <[email protected]>
Date: Mon, 28 Feb 2011 18:11:27 -0800
Subject: USB: Add support for SuperSpeed isoc endpoints
From: Paul Zimmerman <[email protected]>
commit 500132a0f26ad7d9916102193cbc6c1b1becb373 upstream.
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 <[email protected]>
Signed-off-by: Sarah Sharp <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/usb/core/urb.c | 11 ++++++++++-
include/linux/usb/ch9.h | 2 ++
2 files changed, 12 insertions(+), 1 deletion(-)
--- a/drivers/usb/core/urb.c
+++ b/drivers/usb/core/urb.c
@@ -366,7 +366,16 @@ int usb_submit_urb(struct urb *urb, gfp_
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);
--- a/include/linux/usb/ch9.h
+++ b/include/linux/usb/ch9.h
@@ -575,6 +575,8 @@ struct usb_ss_ep_comp_descriptor {
#define USB_DT_SS_EP_COMP_SIZE 6
/* Bits 4:0 of bmAttributes if this is a bulk endpoint */
#define USB_SS_MAX_STREAMS(p) (1 << (p & 0x1f))
+/* Bits 1:0 of bmAttributes if this is an isoc endpoint */
+#define USB_SS_MULT(p) (1 + ((p) & 0x3))
/*-------------------------------------------------------------------------*/
Patches currently in stable-queue which might be from
[email protected] are
queue-2.6.37/usb-add-support-for-superspeed-isoc-endpoints.patch
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