On Wed Jan 29, 2025 at 8:52 AM AEST, Paul Mackerras wrote:
> This uses the 'wait' instruction to pause instruction execution when
> idle until an interrupt occurs.
>
> Signed-off-by: Paul Mackerras <pau...@ozlabs.org>
> ---
> arch/powerpc/platforms/microwatt/setup.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/arch/powerpc/platforms/microwatt/setup.c
> b/arch/powerpc/platforms/microwatt/setup.c
> index 5e1c0997170d..97828a99780d 100644
> --- a/arch/powerpc/platforms/microwatt/setup.c
> +++ b/arch/powerpc/platforms/microwatt/setup.c
> @@ -34,10 +34,19 @@ static void __init microwatt_setup_arch(void)
> microwatt_rng_init();
> }
>
> +static void microwatt_idle(void)
> +{
> + if (!prep_irq_for_idle())
> + return;
> +
> + __asm__ __volatile__ ("wait");
> +}
Does wait cause MSR[EE] to be set? If not, do you need to use
prep_irq_for_idle_irqsoff() here maybe?
Thanks,
Nick
> +
> define_machine(microwatt) {
> .name = "microwatt",
> .compatible = "microwatt-soc",
> .init_IRQ = microwatt_init_IRQ,
> .setup_arch = microwatt_setup_arch,
> .progress = udbg_progress,
> + .power_save = microwatt_idle,
> };
