[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <Pine.LNX.4.44L0.1310301033040.1312-100000@iolanthe.rowland.org>
Date: Wed, 30 Oct 2013 10:35:45 -0400 (EDT)
From: Alan Stern <stern@...land.harvard.edu>
To: David Cohen <david.a.cohen@...ux.intel.com>
cc: balbi@...com, <gregkh@...uxfoundation.org>,
<linux-usb@...r.kernel.org>, <linux-kernel@...r.kernel.org>
Subject: Re: [RFC/PATCH v2 1/3] usb: gadget: add quirks field to struct
usb_gadget
On Tue, 29 Oct 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 'quirks' field to struct usb_gadget and the first quirk
> called USB_GADGET_QUIRK_EP_OUT_ALIGNED_SIZE necessary to inform when
> controller's epout requires buffer size to be aligned to MaxPacketSize.
>
> Signed-off-by: David Cohen <david.a.cohen@...ux.intel.com>
> ---
> include/linux/usb/gadget.h | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
> index 942ef5e..7014ad9 100644
> --- a/include/linux/usb/gadget.h
> +++ b/include/linux/usb/gadget.h
> @@ -540,6 +540,11 @@ struct usb_gadget {
> struct device dev;
> unsigned out_epnum;
> unsigned in_epnum;
> +
> + u32 quirks;
> +/* epout requires buffer size to be aligned to MaxPacketSize */
> +#define USB_GADGET_QUIRK_EP_OUT_ALIGNED_SIZE (1 << 0)
If you decide to go through with this, it might be better to define a
series of single-bit flags instead of a single "quirks" field. For
example:
unsigned quirk_ep_out_aligned_size:1;
Yes, other people (including me!) have done it your way in the past,
but now this seems to make more sense.
Alan Stern
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists