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

Peng Fan
2025-09-22T02:21:36Z

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().

This change improves power efficiency without compromising wakeup
functionality.

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);

genpd_lock(genpd);

--
2.37.1