linux-kernel - Re: [RFC/PATCH v2 1/3] usb: gadget: add quirks field to struct usb

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

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/