Re: [PATCH 0/2] braille: nbcon: Allow using a serial driver converted to nbcon API as a Braille console

[Petr Mladek]

On Fri 2026-09-25 17:11:44, John Ogness wrote:
> On 2026-09-25, Petr Mladek <pmladek@xxxxxxxx> wrote:
> >> > This shows that braille_write() is called form printk() even when
> >> > braille_co is not in console_list. It is called via vt_console_print()
> >> > because the graphical console driver (ttyX) is registered.
> >> 
> >> But isn't that a bug? I thought Braille consoles were not supposed to be
> >> handled by printk(). Even in this new series you added that exact
> >> comment.
> >
> > I believe that it is not a bug. I understand it the way that the
> > Braille device should show everything that is shown on the virtual
> > terminal. It should show the printk() messages when they are
> > printed there by the related console driver.
> >
> > It is just that printk() is only one source of messages shown
> > on the terminal. The vt code maintains what is displayed.
> 
> But how do you register "the terminal" so that printk messages appear
> there?

I used on the command line:

	console=brl,ttyS0,115200 console=tty0

The serial console driver is not in console_list. But it shows
all printk() messages because tty0 is in console_list and
the messages are shown there.

Best Regards,
Petr