Re: [PATCH V2 3/3] serial: stm32: add earlycon support

[Geert Uytterhoeven]

Hi Valentin,

On Fri, Apr 8, 2022 at 3:14 PM Valentin Caron
<valentin.caron@xxxxxxxxxxx> wrote:
> Add early console support in stm32 uart driver.
>
> Signed-off-by: Alexandre Torgue <alexandre.torgue@xxxxxxxxxxx>
> Signed-off-by: Valentin Caron <valentin.caron@xxxxxxxxxxx>

Thanks for your patch!

> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -1264,6 +1264,12 @@
>                         address must be provided, and the serial port must
>                         already be setup and configured.
>
> +               stm32,<addr>
> +                       Use early console provided by ST Microelectronics
> +                       serial driver for STM32 SoCs. A valid base address
> +                       must be provided, and the serial port must already
> +                       be setup and configured.

Why do you need this parameter?

Given this driver uses DT, can't it figure out the serial port address
from chosen/stdout-path?

+OF_EARLYCON_DECLARE(stm32, "st,stm32h7-uart", early_stm32_h7_serial_setup);
+OF_EARLYCON_DECLARE(stm32, "st,stm32f7-uart", early_stm32_f7_serial_setup);
+OF_EARLYCON_DECLARE(stm32, "st,stm32-uart", early_stm32_f4_serial_setup);

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds