Re: [PATCH v3 1/2] serial: earlycon: add uart_clk_freq parameter

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Sun, Jul 12, 2026 at 04:36:17PM +0000, Markus Probst wrote:
> On Fri, 2026-07-10 at 14:36 +0200, Greg Kroah-Hartman wrote:
> > On Mon, Jun 15, 2026 at 12:40:21AM +0000, Markus Probst wrote:
> > > Add function `setup_earlycon_with_uartclk`. This allows the
> > > options string to be reused with `add_preferred_console`, while still
> > > allowing to set the uart clock frequency. This will be used in the
> > > following commit ("ACPI: SPCR: Support UART clock frequency field").
> > > 
> > > No logical change intended.
> > > 
> > > Signed-off-by: Markus Probst <markus.probst@posteo.de>
> > > ---
> > >  drivers/tty/serial/earlycon.c | 17 ++++++++++++-----
> > >  include/linux/serial_core.h   | 11 +++++++++--
> > >  2 files changed, 21 insertions(+), 7 deletions(-)
> > > 
> > > diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c
> > > index ab9af37f6cda..5a20fe9e3fb6 100644
> > > --- a/drivers/tty/serial/earlycon.c
> > > +++ b/drivers/tty/serial/earlycon.c
> > > @@ -135,11 +135,14 @@ static int __init parse_options(struct earlycon_device *device, char *options)
> > >  	return 0;
> > >  }
> > >  
> > > -static int __init register_earlycon(char *buf, const struct earlycon_id *match)
> > > +static int __init register_earlycon(char *buf, unsigned int uart_clk_freq,
> > > +				    const struct earlycon_id *match)
> > >  {
> > >  	int err;
> > >  	struct uart_port *port = &early_console_dev.port;
> > >  
> > > +	port->uartclk = uart_clk_freq;
> > 
> > This looks like a logical change, the code today does not do that
> > anywhere, right?
> 
> `register_earlycon` only gets executed once.
> Thus early_console_dev.port->uartclk is always 0.
> Since all current callers in this patch series use `setup_earlycon`,
> the uart_clk_freq parameter is also always 0.
> 
> So in case of behaviour/logic, this line does nothing without the 2.
> patch.

Then it belongs in the second patch, right?

thanks,

greg k-h