[PATCH 13/13] Nokia RX-51: Enable usbtty serial console by default

Andy Shevchenko
2020-12-27T16:42:19Z

On Sun, Dec 27, 2020 at 6:35 PM Pali Roh?r <pali@kernel.org> wrote:
> On Sunday 27 December 2020 18:28:25 Andy Shevchenko wrote:
> > On Sun, Nov 29, 2020 at 6:53 PM Pali Roh?r <pali@kernel.org> wrote:
> > >
> > > Now when usbtty serial console is fixed in U-Boot enable it for Nokia RX-51
> > > board by default.
> > >
> > > CONFIG_CONSOLE_MUX is already used and U-Boot console is available for
> > > all in/out devices. Therefore there is no need to have separate commands
> > > 'run sercon', 'run usbcon' and 'run vgacon', so remove them.
> > >
> > > As space for U-Boot is limited to 256kB, disable some other unused options
> > > so CONFIG_USB_TTY can be enabled.
> > >
> > > Nokia RX-51 does not have easily accessible UART serial console so the only
> > > option for easy debugging is to use device's keyboard+screen or this usbtty
> > > serial console over USB.
> >
> > I think it's not a good idea to revive usbtty.
>
> Well, but u-boot does not support anything else for Nokia N900. And main
> issues here are musb bugs which this patch series is fixing. For
> debugging is serial console (e.g. usbtty) needed.

I'm not against musb fixes, I'm against promoting usbtty.
Why composite + f_serial can't be used for that?

> > I was recently playing around f_serial.c (I can send you the half
> > baked stuff, which by a lot of twisted code in DWC3 driver is not
> > working properly, actually almost not working) and I think that would
> > be the right thing to do.
> >
> > usbtty quite old, intrusive way of serial console via USB supported
> > only by outdated hardware (like this Nokia N-900), while f_serial
> > gotta work on better recent base. And I believe musb should be, if
> > needed, patched to support composite devices.
> >
> > So, kinda disagreement from my side as a summary on this.
> > But disclaimer, I'm not a maintainer here, just my 2 cents.

--
With Best Regards,
Andy Shevchenko