[v3,1/3] usb/gadget: Fix "high bandwidth" check in usb_gadget_ep_match_desc()

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

On Fri, 2018-01-12 at 10:53 -0500, Alan Stern wrote:
> On Fri, 12 Jan 2018, Benjamin Herrenschmidt wrote:
> 
> > The current code tries to test for bits that are masked out by
> > usb_endpoint_maxp(). Instead, use the proper accessor to access
> > the new high bandwidth bits.
> > 
> > Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> > ---
> 
> Shouldn't this fix be queued for the stable kernels too?

Not sure, I'll let you decide. I noticed that by code inspection ages
ago, and posted the fix at least 2 or 3 times already but nobody picked
it up so I left it in my series and keep re-posting it :-) The bug
doesn't actually affect me.

Cheers,
Ben.

> Alan Stern
> 
> >  drivers/usb/gadget/udc/core.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c
> > index 1b3efb14aec7..ac0541529499 100644
> > --- a/drivers/usb/gadget/udc/core.c
> > +++ b/drivers/usb/gadget/udc/core.c
> > @@ -912,7 +912,7 @@ int usb_gadget_ep_match_desc(struct usb_gadget *gadget,
> >               return 0;
> >  
> >       /* "high bandwidth" works only at high speed */
> > -     if (!gadget_is_dualspeed(gadget) && usb_endpoint_maxp(desc) & (3<<11))
> > +     if (!gadget_is_dualspeed(gadget) && usb_endpoint_maxp_mult(desc) > 1)
> >               return 0;
> >  
> >       switch (type) {
---
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html