Re: [PATCH] media: dvb-usb: Fix unexpected infinite loop in dvb_usb_read_remote_control()

[Zheng Yejian <zhengyejian1@xxxxxxxxxx>]

On 2024/4/30 17:36, Sean Young wrote:
> On Tue, Apr 30, 2024 at 05:19:56PM +0800, Zheng Yejian wrote:
> > Thanks for your suggestion!
> > Do you mean the following change? If it is ok, I'll send a v2!
> >
> > diff --git a/drivers/media/usb/dvb-usb/dvb-usb-init.c b/drivers/media/usb/dvb-usb/dvb-usb-init.c
> > index fbf58012becd..2a8395d6373c 100644
> > --- a/drivers/media/usb/dvb-usb/dvb-usb-init.c
> > +++ b/drivers/media/usb/dvb-usb/dvb-usb-init.c
> > @@ -23,6 +23,23 @@ static int dvb_usb_force_pid_filter_usage;
> >   module_param_named(force_pid_filter_usage, dvb_usb_force_pid_filter_usage, int, 0444);
> >   MODULE_PARM_DESC(force_pid_filter_usage, "force all dvb-usb-devices to use a PID filter, if any (default: 0).");
> >
> > +static int dvb_usb_clear_halt(struct dvb_usb_device *d, u8 endpoint)
>
> I don't think this is a good function name; we are checking that the
> endpoint is correct and also clearing halts.
>
> How about: dvb_usb_check_bulk_endpoint()

Sure, I'll do it in v2!

--
Thank,
Zheng Yejian

> Looks good otherwise
>
> Sean
>
> > +{
> > +       if (endpoint) {
> > +               int ret;
> > +
> > +               ret = usb_pipe_type_check(d->udev, usb_sndbulkpipe(d->udev, endpoint));
> > +               if (ret)
> > +                       return ret;
> > +               ret = usb_pipe_type_check(d->udev, usb_rcvbulkpipe(d->udev, endpoint));
> > +               if (ret)
> > +                       return ret;
> > +               usb_clear_halt(d->udev, usb_sndbulkpipe(d->udev, endpoint));
> > +               usb_clear_halt(d->udev, usb_rcvbulkpipe(d->udev, endpoint));
> > +       }
> > +       return 0;
> > +}
> > +
> >   static int dvb_usb_adapter_init(struct dvb_usb_device *d, short *adapter_nrs)
> >   {
> >          struct dvb_usb_adapter *adap;
> > @@ -103,10 +120,12 @@ static int dvb_usb_adapter_init(struct dvb_usb_device *d, short *adapter_nrs)
> >           * when reloading the driver w/o replugging the device
> >           * sometimes a timeout occurs, this helps
> >           */
> > -       if (d->props.generic_bulk_ctrl_endpoint != 0) {
> > -               usb_clear_halt(d->udev, usb_sndbulkpipe(d->udev, d->props.generic_bulk_ctrl_endpoint));
> > -               usb_clear_halt(d->udev, usb_rcvbulkpipe(d->udev, d->props.generic_bulk_ctrl_endpoint));
> > -       }
> > +       ret = dvb_usb_clear_halt(d, d->props.generic_bulk_ctrl_endpoint);
> > +       if (ret)
> > +               goto frontend_init_err;
> > +       ret = dvb_usb_clear_halt(d, d->props.generic_bulk_ctrl_endpoint_response);
> > +       if (ret)
> > +               goto frontend_init_err;
> >
> >          return 0;
> >
> > --
> > Thanks,
> > Zheng Yejian
> >
> > > Thanks
> > >
> > > Sean