Messages in this thread Patch in this message | | | Date | Mon, 21 Mar 2011 16:06:50 -0700 | From | Greg KH <> | Subject | [51/87] USB: Add support for SuperSpeed isoc endpoints |
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2.6.37-stable review patch. If anyone has any objections, please let us know.
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From: Paul Zimmerman <Paul.Zimmerman@synopsys.com>
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 <paulz@synopsys.com> Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- 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)) /*-------------------------------------------------------------------------*/
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