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From:   Andrey Konovalov <andreyknvl@gmail.com>
Date:   Sun, 30 Jan 2022 22:58:42 +0100
Message-ID: <CA+fCnZc4kavuHbGXAbzQJSLG=f9Oc--O-H=OT_xkKb0AooyyAQ@mail.gmail.com>
Subject: Re: [PATCH] usb: raw-gadget: fix handling of dual-direction-capable endpoints
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     Felipe Balbi <balbi@kernel.org>,
        USB list <linux-usb@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Jann Horn <jannh@google.com>, stable@vger.kernel.org
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On Wed, Jan 26, 2022 at 11:37 PM Andrey Konovalov <andreyknvl@gmail.com> wrote:
>
> On Wed, Jan 26, 2022 at 11:31 PM Jann Horn <jannh@google.com> wrote:
> >
> > On Wed, Jan 26, 2022 at 11:12 PM Andrey Konovalov <andreyknvl@gmail.com> wrote:
> > > On Wed, Jan 26, 2022 at 9:52 PM Jann Horn <jannh@google.com> wrote:
> > > >
> > > > Under dummy_hcd, every available endpoint is *either* IN or OUT capable.
> > > > But with some real hardware, there are endpoints that support both IN and
> > > > OUT. In particular, the PLX 2380 has four available endpoints that each
> > > > support both IN and OUT.
> > > >
> > > > raw-gadget currently gets confused and thinks that any endpoint that is
> > > > usable as an IN endpoint can never be used as an OUT endpoint.
> > > >
> > > > Fix it by looking at the direction in the configured endpoint descriptor
> > > > instead of looking at the hardware capabilities.
> > > >
> > > > With this change, I can use the PLX 2380 with raw-gadget.
> > > >
> > > > Fixes: f2c2e717642c ("usb: gadget: add raw-gadget interface")
> > > > Signed-off-by: Jann Horn <jannh@google.com>
> > > > ---
> > > >  drivers/usb/gadget/legacy/raw_gadget.c | 2 +-
> > > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > >
> > > > diff --git a/drivers/usb/gadget/legacy/raw_gadget.c b/drivers/usb/gadget/legacy/raw_gadget.c
> > > > index c5a2c734234a..d86c3a36441e 100644
> > > > --- a/drivers/usb/gadget/legacy/raw_gadget.c
> > > > +++ b/drivers/usb/gadget/legacy/raw_gadget.c
> > > > @@ -1004,7 +1004,7 @@ static int raw_process_ep_io(struct raw_dev *dev, struct usb_raw_ep_io *io,
> > > >                 ret = -EBUSY;
> > > >                 goto out_unlock;
> > > >         }
> > > > -       if ((in && !ep->ep->caps.dir_in) || (!in && ep->ep->caps.dir_in)) {
> > > > +       if (in != usb_endpoint_dir_in(ep->ep->desc)) {
> > > >                 dev_dbg(&dev->gadget->dev, "fail, wrong direction\n");
> > > >                 ret = -EINVAL;
> > > >                 goto out_unlock;
> > > >
> > > > base-commit: 0280e3c58f92b2fe0e8fbbdf8d386449168de4a8
> > > > --
> > > > 2.35.0.rc0.227.g00780c9af4-goog
> > > >
>
> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
> Tested-by: Andrey Konovalov <andreyknvl@gmail.com>

Greg, could you PTAL and pick this up?

It also makes sense to include this fix into stable kernels.

Cc: <stable@vger.kernel.org>

Thanks!