Re: [PATCH v4 2/5] PM: domains: Allow power-off for out-of-band wakeup-capable devices

Dhruva Gole
2025-09-23T09:44:47Z

On Sep 22, 2025 at 10:21:07 +0800, Peng Fan wrote:
> Currently, if a device is configured as a system wakeup source, the PM
> domain core avoids powering off its power domain during system-wide
> suspend. However, this can lead to unnecessary power consumption,
> especially for devices whose wakeup logic resides in an always-on domain,
> i.e., devices with out-of-band wakeup capability.
>
> To address this, add a check for device_out_band_wakeup() in
> genpd_finish_suspend(). If the device supports out-of-band wakeup, its
> power domain can be safely powered off, just like regular devices without
> wakeup enabled. And same check in genpd_finish_resume().

Seems very well structured now! Thanks.

>
> This change improves power efficiency without compromising wakeup
> functionality.

On a lighter note-
This seems like an AI generated sentence to me :P

I've often seen LLMs throw around terms like improve code / power
efficiency, etc...

>
> Signed-off-by: Peng Fan <peng.fan@nxp.com>
> ---
> drivers/pmdomain/core.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/pmdomain/core.c b/drivers/pmdomain/core.c
> index 61c2277c9ce39fcd2f7e77df549626e49a4d5310..4925bc1c441078a8d38600192ee696bf550e80f0 100644
> --- a/drivers/pmdomain/core.c
> +++ b/drivers/pmdomain/core.c
> @@ -1545,7 +1545,8 @@ static int genpd_finish_suspend(struct device *dev,
> if (ret)
> return ret;
>
> - if (device_awake_path(dev) && genpd_is_active_wakeup(genpd))
> + if (device_awake_path(dev) && genpd_is_active_wakeup(genpd) &&
> + !device_out_band_wakeup(dev))
> return 0;
>
> if (genpd->dev_ops.stop && genpd->dev_ops.start &&
> @@ -1600,7 +1601,8 @@ static int genpd_finish_resume(struct device *dev,
> if (IS_ERR(genpd))
> return -EINVAL;
>
> - if (device_awake_path(dev) && genpd_is_active_wakeup(genpd))
> + if (device_awake_path(dev) && genpd_is_active_wakeup(genpd) &&
> + !device_out_band_wakeup(dev))
> return resume_noirq(dev);

Reviewed-by: Dhruva Gole <d-gole@ti.com>

--
Best regards,
Dhruva Gole
Texas Instruments Incorporated