On Mon, Jun 02, 2025 at 10:19:03AM -0300, Hiago De Franco wrote: > From: Hiago De Franco <[email protected]> > > This helper function returns the current power status of a given generic > power domain. >
Please correct me if I'm wrong, but this returns the momentary status of the device's associated genpd, and as genpds can be shared among devices wouldn't there be a risk that you think the genpd is on but then that other device powers it off? > As example, remoteproc/imx_rproc.c can now use this function to check > the power status of the remote core to properly set "attached" or > "offline" modes. I presume this example works because there is a dedicated, single usage, genpd for the remoteproc instance? > > Suggested-by: Ulf Hansson <[email protected]> > Signed-off-by: Hiago De Franco <[email protected]> > --- > v4: New patch. > --- > drivers/pmdomain/core.c | 27 +++++++++++++++++++++++++++ > include/linux/pm_domain.h | 6 ++++++ > 2 files changed, 33 insertions(+) > > diff --git a/drivers/pmdomain/core.c b/drivers/pmdomain/core.c > index ff5c7f2b69ce..bcb74d10960c 100644 > --- a/drivers/pmdomain/core.c > +++ b/drivers/pmdomain/core.c > @@ -758,6 +758,33 @@ int dev_pm_genpd_rpm_always_on(struct device *dev, bool > on) > } > EXPORT_SYMBOL_GPL(dev_pm_genpd_rpm_always_on); > > +/** > + * dev_pm_genpd_is_on - Get device's power status Functions in kernel-doc should have () prefix > + * > + * @dev: Device to get the current power status > + * > + * This function checks whether the generic power domain is on or not by > + * verifying if genpd_status_on equals GENPD_STATE_ON. > + * If my understanding is correct, I'd like a warning here saying that this is dangerous if the underlying genpd is shared. Regards, Bjorn > + * Return: 'true' if the device's power domain is on, 'false' otherwise. > + */ > +bool dev_pm_genpd_is_on(struct device *dev) > +{ > + struct generic_pm_domain *genpd; > + bool is_on; > + > + genpd = dev_to_genpd_safe(dev); > + if (!genpd) > + return false; > + > + genpd_lock(genpd); > + is_on = genpd_status_on(genpd); > + genpd_unlock(genpd); > + > + return is_on; > +} > +EXPORT_SYMBOL_GPL(dev_pm_genpd_is_on); > + > /** > * pm_genpd_inc_rejected() - Adjust the rejected/usage counts for an > idle-state. > * > diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h > index 0b18160901a2..c12580b6579b 100644 > --- a/include/linux/pm_domain.h > +++ b/include/linux/pm_domain.h > @@ -301,6 +301,7 @@ void dev_pm_genpd_synced_poweroff(struct device *dev); > int dev_pm_genpd_set_hwmode(struct device *dev, bool enable); > bool dev_pm_genpd_get_hwmode(struct device *dev); > int dev_pm_genpd_rpm_always_on(struct device *dev, bool on); > +bool dev_pm_genpd_is_on(struct device *dev); > > extern struct dev_power_governor simple_qos_governor; > extern struct dev_power_governor pm_domain_always_on_gov; > @@ -393,6 +394,11 @@ static inline int dev_pm_genpd_rpm_always_on(struct > device *dev, bool on) > return -EOPNOTSUPP; > } > > +static inline bool dev_pm_genpd_is_on(struct device *dev) > +{ > + return false; > +} > + > #define simple_qos_governor (*(struct dev_power_governor *)(NULL)) > #define pm_domain_always_on_gov (*(struct dev_power_governor > *)(NULL)) > #endif > -- > 2.39.5 >
