[PATCH] riscv: sbi: Prefer SRST shutdown over legacy

[Anup Patel]

On Fri, Nov 14, 2025 at 12:29 PM Mayuresh Chitale
<mchitale at ventanamicro.com> wrote:
>
> Currently, the sbi_init() always attempts to register the legacy shutdown
> function as the sys-off handler which is fine when RISCV_SBI_V01 is not
> enabled. However, if RISCV_SBI_V01 is enabled in the kernel and the SBI
> v0.1 is not supported by the underlying SBI implementation then the
> legacy shutdown fails. Fix this by not registering the legacy shutdown
> when SRST shutdown is available.
>
> Fixes: 70ddf86d76c1 ("riscv: sbi: Switch to new sys-off handler API")
> Signed-off-by: Mayuresh Chitale <mchitale at ventanamicro.com>

LGTM.

Reviewed-by: Anup Patel <anup at brainfault.org>

Regards,
Anup

> ---
>  arch/riscv/kernel/sbi.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/arch/riscv/kernel/sbi.c b/arch/riscv/kernel/sbi.c
> index 5e8cde055264..c443337056ab 100644
> --- a/arch/riscv/kernel/sbi.c
> +++ b/arch/riscv/kernel/sbi.c
> @@ -648,9 +648,9 @@ int sbi_debug_console_read(char *bytes, unsigned int num_bytes)
>
>  void __init sbi_init(void)
>  {
> +       bool srst_power_off = false;
>         int ret;
>
> -       sbi_set_power_off();
>         ret = sbi_get_spec_version();
>         if (ret > 0)
>                 sbi_spec_version = ret;
> @@ -683,6 +683,7 @@ void __init sbi_init(void)
>                     sbi_probe_extension(SBI_EXT_SRST)) {
>                         pr_info("SBI SRST extension detected\n");
>                         register_platform_power_off(sbi_srst_power_off);
> +                       srst_power_off = true;
>                         sbi_srst_reboot_nb.notifier_call = sbi_srst_reboot;
>                         sbi_srst_reboot_nb.priority = 192;
>                         register_restart_handler(&sbi_srst_reboot_nb);
> @@ -702,4 +703,7 @@ void __init sbi_init(void)
>                 __sbi_send_ipi  = __sbi_send_ipi_v01;
>                 __sbi_rfence    = __sbi_rfence_v01;
>         }
> +
> +       if (!srst_power_off)
> +               sbi_set_power_off();
>  }
> --
> 2.43.0
>
>
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