On Thu, 8 Dec 2011, Sebastian Andrzej Siewior wrote:
> This patch adds sg support to dummy_hcd. It seems that uas is not able
> to work with a hcd which does not support sg only based transfers.
>
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
> ---
> drivers/usb/gadget/dummy_hcd.c | 78 ++++++++++++++++++++++++++++++++++++----
> 1 files changed, 71 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/usb/gadget/dummy_hcd.c b/drivers/usb/gadget/dummy_hcd.c
> index bfba4aa..5ba8e18 100644
> --- a/drivers/usb/gadget/dummy_hcd.c
> +++ b/drivers/usb/gadget/dummy_hcd.c
> @@ -1140,21 +1142,82 @@ static int dummy_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
> return rc;
> }
>
> +static void forward_miter(struct sg_mapping_iter *miter, u32 bytes)
> +{
> + u32 done = 0;
> +
> + /* press the forward button on the URB side */
> + if (!bytes)
> + return;
> + do {
> + done += miter->length;
> + if (bytes > done) {
> + sg_miter_next(miter);
> + continue;
> + }
> + if (bytes == done)
> + break;
> +
> + miter->consumed = miter->length - (done - bytes);
> + break;
> + } while (1);
> + sg_miter_next(miter);
> +}
This entire routine could be eliminated if you put the sg_mapping_iter
thingy inside the urbp private structure. Don't start the iteration
until you're ready to use it, of course.
Alan Stern
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