From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg KH Subject: Re: [PATCH 1/9] usb: core: Add a helper function to check the validity of EP type in URB Date: Tue, 10 Oct 2017 15:53:49 +0200 Message-ID: <20171010135349.GH6418@kroah.com> References: <20171010133819.10567-1-tiwai@suse.de> <20171010133819.10567-2-tiwai@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20171010133819.10567-2-tiwai-l3A5Bk7waGM@public.gmane.org> Sender: linux-usb-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Takashi Iwai Cc: alsa-devel-K7yf7f+aM1XWsZ/bQMPhNw@public.gmane.org, linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Andrey Konovalov List-Id: alsa-devel@alsa-project.org On Tue, Oct 10, 2017 at 03:38:11PM +0200, Takashi Iwai wrote: > This patch adds a new helper function to perform a sanity check of the > given URB to see whether it contains a valid endpoint. It's a light- > weight version of what usb_submit_urb() does, but without the kernel > warning followed by the stack trace, just returns an error code. > > Especially for a driver that doesn't parse the descriptor but fills > the URB with the fixed endpoint (e.g. some quirks for non-compliant > devices), this kind of check is preferable at the probe phase before > actually submitting the urb. > > Signed-off-by: Takashi Iwai > --- > drivers/usb/core/urb.c | 28 +++++++++++++++++++++++++--- > include/linux/usb.h | 2 ++ > 2 files changed, 27 insertions(+), 3 deletions(-) > > diff --git a/drivers/usb/core/urb.c b/drivers/usb/core/urb.c > index 47903d510955..580dfaec8af7 100644 > --- a/drivers/usb/core/urb.c > +++ b/drivers/usb/core/urb.c > @@ -187,6 +187,31 @@ EXPORT_SYMBOL_GPL(usb_unanchor_urb); > > /*-------------------------------------------------------------------*/ > > +static const int pipetypes[4] = { > + PIPE_CONTROL, PIPE_ISOCHRONOUS, PIPE_BULK, PIPE_INTERRUPT > +}; > + > +/** > + * usb_urb_ep_check_type - sanity check of endpoint in the given urb > + * @urb: urb to be checked > + * > + * This performs a light-weight sanity check for the endpoint in the > + * given urb. It returns 0 if the urb contains a valid endpoint, otherwise > + * a negative error code. > + */ > +int usb_urb_ep_check_type(const struct urb *urb) > +{ > + const struct usb_host_endpoint *ep; > + > + ep = usb_pipe_endpoint(urb->dev, urb->pipe); > + if (!ep) > + return -EINVAL; > + if (usb_pipetype(urb->pipe) != pipetypes[usb_endpoint_type(&ep->desc)]) > + return -EINVAL; > + return 0; > +} > +EXPORT_SYMBOL_GPL(usb_urb_ep_check_type); > + > /** > * usb_submit_urb - issue an asynchronous transfer request for an endpoint > * @urb: pointer to the urb describing the request > @@ -326,9 +351,6 @@ EXPORT_SYMBOL_GPL(usb_unanchor_urb); > */ > int usb_submit_urb(struct urb *urb, gfp_t mem_flags) > { > - static int pipetypes[4] = { > - PIPE_CONTROL, PIPE_ISOCHRONOUS, PIPE_BULK, PIPE_INTERRUPT > - }; > int xfertype, max; > struct usb_device *dev; > struct usb_host_endpoint *ep; Can you also call usb_urb_ep_check_type() in usb_submit_urb()? thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html