Re: [PATCH v3 2/3] serial: sh-sci: Drop check for zero baud rate from uart_get_baud_rate()

[Hugo Villeneuve]

Hi,

On Wed, 22 Apr 2026 10:59:23 +0200
Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote:

> Hi Biju,
> 
> On Wed, 22 Apr 2026 at 09:26, Biju Das <biju.das.jz@xxxxxxxxxxxxxx> wrote:
> > > From: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> > > On Mon, 20 Apr 2026 at 16:04, Biju <biju.das.au@xxxxxxxxx> wrote:
> > > > From: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> > > >
> > > > On DT systems, a zero baud rate from uart_get_baud_rate() is not

The fact that uart_get_baud_rate() cannot return zero is not related
to the system using DT or not, so I would drop this "On DT systems, "
from the commit message.

> > > > possible even earlycon derives its bit rate from chosen/stdout-path.
> > > > The zero baud guard and its associated done label are therefore dead code. So remove it.
> > > >
> > > > Also drop the unused done label from rsci_set_termios().
> > > >
> > > > Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> > >
> > > > --- a/drivers/tty/serial/sh-sci.c
> > > > +++ b/drivers/tty/serial/sh-sci.c
> > > > @@ -2719,8 +2719,6 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
> > > >                 max_freq = max(max_freq, s->clk_rates[i]);
> > > >
> > > >         baud = uart_get_baud_rate(port, termios, old, 0, max_freq / min_sr(s));
> > > > -       if (!baud)
> > > > -               goto done;
> > > >
> > > >         /*
> > > >          * There can be multiple sources for the sampling clock.  Find
> > > > the one
> > >
> > > I am afraid you are missing that sh-sci is also used on SH, without DT?
> >
> > Ok, please share your thoughts to handle divide_by_zero fault for
> > SH platforms on the code path after done label??
> 
> Someone has to check on an SH platform (or qemu rts7751r2d) if
> this can happen. It might have been broken along the road, as people
> only use earlyprintk when debugging a problem that requires it.

Geert: this "goto done" is not related to the earlyprintk block, which
is untouched by this patch?

-- 
Hugo Villeneuve