[PATCH v2 08/13] firmware: arm_scmi: Harden clock protocol initialization

[Geert Uytterhoeven]

Hi Cristian,

On Tue, 10 Mar 2026 at 19:56, Cristian Marussi <cristian.marussi at arm.com> wrote:
> Add proper error handling on failure to enumerate clocks features or
> rates.
>
> Signed-off-by: Cristian Marussi <cristian.marussi at arm.com>

Thanks for your patch!

> --- a/drivers/firmware/arm_scmi/clock.c
> +++ b/drivers/firmware/arm_scmi/clock.c

> @@ -1143,8 +1149,12 @@ static int scmi_clock_protocol_init(const struct scmi_protocol_handle *ph)
>         for (clkid = 0; clkid < cinfo->num_clocks; clkid++) {
>                 cinfo->clkds[clkid].id = clkid;
>                 ret = scmi_clock_attributes_get(ph, clkid, cinfo);
> -               if (!ret)
> -                       scmi_clock_describe_rates_get(ph, clkid, cinfo);
> +               if (ret)
> +                       return ret;

This change breaks R-Car X5H with SCP FW SDKv4.28.0, as some clocks
do not support the SCMI CLOCK_ATTRIBUTES command.
Before, these clocks were still instantiated, but were further unusable.
After, the whole clock driver fails to initialize, and no SCMI clocks
are available at all.

> +
> +               ret = scmi_clock_describe_rates_get(ph, clkid, cinfo);
> +               if (ret)
> +                       return ret;
>         }
>
>         if (PROTOCOL_REV_MAJOR(ph->version) >= 0x3) {

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org

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