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

Pali Rohár
2020-12-27T16:50:43Z

On Sunday 27 December 2020 18:42:19 Andy Shevchenko wrote:
> 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?

Because nobody looked at it and invested time in it. usbtty was there
for a long time and is working fine right now (with these musb patches).

> > > 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 only by outdated hardware (like this Nokia N-900), while f_serial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