dOn Tue, Dec 10 2013, David Cohen wrote:
> Due to USB controllers may have different restrictions, usb gadget layer
> needs to provide a generic way to inform gadget functions to complain
> with non-standard requirements.
>
> This patch adds 'quirk_ep_out_aligned_size' field to struct usb_gadget
> to inform when controller's epout requires buffer size to be aligned to
> MaxPacketSize. A helper is also provided to align buffer size when
> necessary.
>
> Signed-off-by: David Cohen <david.a.cohen@xxxxxxxxxxxxxxx>
> Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
> Cc: Michal Nazarewicz <mina86@xxxxxxxxxx>
Acked-by: Michal Nazarewicz <mina86@xxxxxxxxxx>
> ---
> include/linux/usb/gadget.h | 20 ++++++++++++++++++++
> 1 file changed, 20 insertions(+)
>
> diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
> index 23b3bfd0a842..cae8a6216551 100644
> --- a/include/linux/usb/gadget.h
> +++ b/include/linux/usb/gadget.h
> @@ -502,6 +502,8 @@ struct usb_gadget_ops {
> * only supports HNP on a different root port.
> * @b_hnp_enable: OTG device feature flag, indicating that the A-Host
> * enabled HNP support.
> + * @quirk_ep_out_aligned_size: epout requires buffer size to be aligned to
> + * MaxPacketSize.
> *
> * Gadgets have a mostly-portable "gadget driver" implementing device
> * functions, handling all usb configurations and interfaces. Gadget
> @@ -541,6 +543,7 @@ struct usb_gadget {
> unsigned b_hnp_enable:1;
> unsigned a_hnp_support:1;
> unsigned a_alt_hnp_support:1;
> + unsigned quirk_ep_out_aligned_size:1;
> };
> #define work_to_gadget(w) (container_of((w), struct usb_gadget, work))
>
> @@ -559,6 +562,23 @@ static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev)
>
>
> /**
> + * usb_ep_align_maybe - returns @len aligned to ep's maxpacketsize if gadget
> + * requires quirk_ep_out_aligned_size, otherwise reguens len.
“returns”
> + * @g: controller to check for quirk
> + * @ep: the endpoint whose maxpacketsize is used to align @len
> + * @len: buffer size's length to align to @ep's maxpacketsize
> + *
> + * This helper is used in case it's required for any reason to check and maybe
> + * align buffer's size to an ep's maxpacketsize.
> + */
> +static inline size_t
> +usb_ep_align_maybe(struct usb_gadget *g, struct usb_ep *ep, size_t len)
> +{
> + return !g->quirk_ep_out_aligned_size ? len :
> + round_up(len, (size_t)ep->desc->wMaxPacketSize);
> +}
> +
> +/**
> * gadget_is_dualspeed - return true iff the hardware handles high speed
> * @g: controller that might support both high and full speeds
> */
--
Best regards, _ _
.o. | Liege of Serenely Enlightened Majesty of o' \,=./ `o
..o | Computer Science, Michał “mina86” Nazarewicz (o o)
ooo +--<mpn@xxxxxxxxxx>--<xmpp:mina86@xxxxxxxxxx>--ooO--(_)--Ooo--
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