Re: [PATCH] cdc-acm: acm_init: Set initial BAUD to B0

[Johan Hovold <johan@kernel.org>]

On Fri, Jul 10, 2020 at 10:46:19AM +0000, Joakim Tjernlund wrote:
> On Fri, 2020-07-10 at 12:34 +0200, Greg KH wrote:
> > 
> > On Fri, Jul 10, 2020 at 11:35:18AM +0200, Joakim Tjernlund wrote:

> > >       tty_set_operations(acm_tty_driver, &acm_ops);
> > > 
> > > -     retval = tty_register_driver(acm_tty_driver);
> > > +     retval = usb_register(&acm_driver);
> > >       if (retval) {
> > >               put_tty_driver(acm_tty_driver);
> > >               return retval;
> > >       }
> > > 
> > > -     retval = usb_register(&acm_driver);
> > > +     retval = tty_register_driver(acm_tty_driver);
> > >       if (retval) {
> > > -             tty_unregister_driver(acm_tty_driver);
> > > +             usb_deregister(&acm_driver);
> > 
> > Why are you switching these around?  I think I know, but you don't
> > really say...
> 
> I wrote:
>    For initial termios to reach USB core, USB driver has to be
>    registered before TTY driver.
> Found out that by trial and error. Isn't that clear enough?

No, that makes no sense at all since USB core does not care about
init_termios.

Johan