Re: [PATCH v2 2/3] usb: gadget: f_fs: add ioctl returning ep descriptor

From: Greg KH
Date: Mon Jul 28 2014 - 02:47:33 EST

On Mon, Jul 28, 2014 at 08:42:44AM +0200, Marek Szyprowski wrote:
> Hello,
> On 2014-07-25 16:15, Michal Nazarewicz wrote:
> >On Fri, Jul 25 2014, Robert Baldyga wrote:
> >>This patch introduces ioctl named FUNCTIONFS_ENDPOINT_DESC, which
> >>returns endpoint descriptor to userspace. It works only if function
> >>is active.
> >I would argue that user space should never need to know the real
> >descriptor. Is this ioctl needed for anything in particular?
> Some proprietary broken usb protocols might embed real physical endpoint
> (or interface) number into the data stream. In such case functionfs driver
> is unable to do proper endpoint/interface number fixup.

Do you have an example of such a messed up thing?

greg k-h
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