[PATCH] lib: utils/reset: Hang the hart after RPMI system reset message

[Samuel Holland]

Hi Rahul,

On 2025-09-03 9:43 AM, Rahul Pathak wrote:
> RPMI system reset is a posted message which
> does not wait for acknowledgement after sending
> the RPMI message to PuC. Call the sbi_hart_hang()
> to hang the hart after performing the system reset
> via RPMI message.
> 
> Fixes: 6a26726e08e4 ("lib/utils: reset: Add RPMI System Reset driver")
> Reported-by: Anup Patel <apatel at ventanamicro.com>
> Signed-off-by: Rahul Pathak <rpathak at ventanamicro.com>
> ---
>  lib/utils/reset/fdt_reset_rpmi.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/lib/utils/reset/fdt_reset_rpmi.c b/lib/utils/reset/fdt_reset_rpmi.c
> index edc53932ccc0..c29715d329c4 100644
> --- a/lib/utils/reset/fdt_reset_rpmi.c
> +++ b/lib/utils/reset/fdt_reset_rpmi.c
> @@ -7,6 +7,7 @@
>   *   Rahul Pathak <rpathak at ventanamicro.com>
>   */
>  
> +#include <sbi/sbi_hart.h>
>  #include <sbi/sbi_error.h>
>  #include <sbi/sbi_system.h>
>  #include <sbi/sbi_console.h>
> @@ -56,6 +57,8 @@ static void rpmi_do_system_reset(u32 reset_type)
>  	if (ret)
>  		sbi_printf("system reset failed [type: %d]: ret: %d\n",
>  			   reset_type, ret);
> +
> +	sbi_hart_hang();
>  }
If rpmi_do_system_reset() returns normally, the generic code will continue to
sbi_exit() and eventually sbi_hsm_hart_wait(). Was that problematic in some way?
You've added a Fixes tag, but it's not clear from the commit message what
problem you observed.

If allowing the driver's .system_reset callback to return is problematic (some
driver implementations hang, some don't), then we should mark the function type
as noreturn and update the remaining drivers as well.

Regards,
Samuel