Re: [PATCH] usb: core: allow zero packet flag for interrupt urbs

From: Hans de Goede
Date: Thu Jul 17 2014 - 06:44:32 EST


Hi,

On 07/17/2014 10:47 AM, Amit Virdi wrote:
> Section 4.4.7.2 of the USB3.0 spec says:
> A zero-length data payload is a valid transfer and may be useful for
> some implementations.
>
> So, extend the logic of allowing URB_ZERO_PACKET to interrupt urbs too.
> Otherwise, the kernel throws error of BOGUS transfer flags.
>
> Signed-off-by: Amit Virdi <amit.virdi@xxxxxx>

Seems sensible to me:

Acked-by: Hans de Goede <hdegoede@xxxxxxxxxx>

Regards,

Hans


> ---
> drivers/usb/core/urb.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/usb/core/urb.c b/drivers/usb/core/urb.c
> index 991386c..a136246 100644
> --- a/drivers/usb/core/urb.c
> +++ b/drivers/usb/core/urb.c
> @@ -460,6 +460,10 @@ int usb_submit_urb(struct urb *urb, gfp_t mem_flags)
> case USB_ENDPOINT_XFER_CONTROL:
> allowed |= URB_NO_FSBR; /* only affects UHCI */
> /* FALLTHROUGH */
> + case USB_ENDPOINT_XFER_INT:
> + if (is_out)
> + allowed |= URB_ZERO_PACKET;
> + /* FALLTHROUGH */
> default: /* all non-iso endpoints */
> if (!is_out)
> allowed |= URB_SHORT_NOT_OK;
>
--
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