[1/2] usb: gadget: Add start_frame to usb_request

[Felipe Balbi <balbi@kernel.org>]

Hi,

Thinh Nguyen <thinh.nguyen@synopsys.com> writes:
> Similar to URB's start_frame, add a field start_frame to the usb_request
> to report the scheduled (micro)frame number of an isochronous transfer.
> This option is useful for debugging purposes.
>
> Signed-off-by: Thinh Nguyen <thinhn@synopsys.com>
> ---
>  include/linux/usb/gadget.h | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
> index e5cd84a0f84a..ed9dbbce55ee 100644
> --- a/include/linux/usb/gadget.h
> +++ b/include/linux/usb/gadget.h
> @@ -50,6 +50,7 @@ struct usb_ep;
>   * @short_not_ok: When reading data, makes short packets be
>   *     treated as errors (queue stops advancing till cleanup).
>   * @dma_mapped: Indicates if request has been mapped to DMA (internal)
> + * @start_frame: the reported (micro)frame of the scheduled isoc transfer
>   * @complete: Function called when request completes, so this request and
>   *	its buffer may be re-used.  The function will always be called with
>   *	interrupts disabled, and it must not sleep.
> @@ -107,6 +108,8 @@ struct usb_request {
>  	unsigned		short_not_ok:1;
>  	unsigned		dma_mapped:1;
>  
> +	int			start_frame;		/* ISO ONLY */

this name is a bit misleading. I can see functions trying to use it to
request that a particular request start on a specific frame. Would
"started_frame" be a better name, perhaps?