Re: [PATCH v1 1/1] riscv: sbi: Introduce system suspend support

Conor Dooley
2023-10-12T13:30:17Z

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Yo,

On Thu, Oct 12, 2023 at 09:21:50AM +0200, Andrew Jones wrote:
> When the SUSP SBI extension is present it implies that the standard
> "suspend to RAM" type is available. Wire it up to the generic
> platform suspend support, also applying the already present support
> for non-retentive CPU suspend. When the kernel is built with
> CONFIG_SUSPEND, one can do 'echo mem > /sys/power/state' to suspend.
> Resumption will occur when a platform-specific wake-up event arrives.
>
> Signed-off-by: Andrew Jones <ajones@ventanamicro.com>

> +static int __init sbi_system_suspend_init(void)
> +{
> + if (!sbi_spec_is_0_1() && sbi_probe_extension(SBI_EXT_SUSP) > 0) {

Random thought I had reading this, was that it'll be possible to have a
firmware that implements SBI < 2.0 that provides the SUSP extension.
FWIW, I don't think that that is problematic, but maybe I am missing
something that would make it so.

Cheers,
Conor.

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