Re: [PATCH 2/2] serial: mctrl_gpio: Support all GPIO suffixes (gpios vs gpio)

[Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>]

Hi Stefan,

On Thu, Aug 8, 2019 at 3:25 PM Stefan Roese <sr@xxxxxxx> wrote:
> This patch fixes a backward compatibility issue, when boards use the
> old style GPIO suffix "-gpio" instead of the new "-gpios". This
> potential problem has been introduced by commit d99482673f95 ("serial:
> mctrl_gpio: Check if GPIO property exisits before requesting it").
>
> This patch now fixes this issue by iterating over all supported GPIO
> suffixes by using the newly introduced for_each_gpio_suffix() helper.
>
> Also, the string buffer is now allocated on the stack to avoid the
> problem of allocation in a loop and its potential failure.
>
> Signed-off-by: Stefan Roese <sr@xxxxxxx>

Do we really need to spread this *-gpio" legacy support all over the kernel?

Seeing the only in-kernel users of legacy "rts-gpio" are

    arch/arm/boot/dts/am335x-nano.dts:      rts-gpio = <&gpio0 13
GPIO_ACTIVE_HIGH>;
    arch/arm/boot/dts/am335x-nano.dts:      rts-gpio = <&gpio2 15
GPIO_ACTIVE_HIGH>;
    arch/arm/boot/dts/am335x-pdu001.dts:    rts-gpio = <&gpio1 9
GPIO_ACTIVE_HIGH>;

and this is handled by omap-serial.c, predating mctrl_gpio, I'd like to
reconsider.

Documentation/devicetree/bindings/serial/serial.txt always described
the "*-gpios"
variants, so there should be no users of the legacy "*-gpio" variants.

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