On Mon, Feb 28, 2011 at 06:11:27PM -0800, Paul Zimmerman wrote:
> Use the Mult and bMaxBurst values from the endpoint companion
> descriptor to calculate the max length of an isoc transfer.
>
> v2 - Add USB_SS_MULT macro to access Mult field of bmAttributes, at
> Sarah's suggestion.
Looks fine to me. Andiry?
Sarah
> Signed-off-by: Paul Zimmerman <paulz@xxxxxxxxxxxx>
> ---
> drivers/usb/core/urb.c | 11 ++++++++++-
> include/linux/usb/ch9.h | 2 ++
> 2 files changed, 12 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/usb/core/urb.c b/drivers/usb/core/urb.c
> index c14fc08..ae334b0 100644
> --- a/drivers/usb/core/urb.c
> +++ b/drivers/usb/core/urb.c
> @@ -366,7 +366,16 @@ int usb_submit_urb(struct urb *urb, gfp_t mem_flags)
> 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);
> diff --git a/include/linux/usb/ch9.h b/include/linux/usb/ch9.h
> index 34316ba..b72f305 100644
> --- a/include/linux/usb/ch9.h
> +++ b/include/linux/usb/ch9.h
> @@ -585,6 +585,8 @@ 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))
>
> /*-------------------------------------------------------------------------*/
>
> --
> 1.6.5.1.69.g36942
>
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