| Message ID | 20250602131906.25751-2-hiagofranco@gmail.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | remoteproc: imx_rproc: allow attaching to running core kicked by the bootloader | expand |
On Mon, Jun 02, 2025 at 10:19:03AM -0300, Hiago De Franco wrote: > From: Hiago De Franco <hiago.franco@toradex.com> > > 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 <ulf.hansson@linaro.org> > Signed-off-by: Hiago De Franco <hiago.franco@toradex.com> > --- > 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 >
On Wed, Jun 11, 2025 at 10:32:28AM -0500, Bjorn Andersson wrote: > On Mon, Jun 02, 2025 at 10:19:03AM -0300, Hiago De Franco wrote: > > From: Hiago De Franco <hiago.franco@toradex.com> > > > > 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? I am not fully familiar with the genpd's, so my knowledge might be limited, but I think this is correct, if the genpd is shared. > > > 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? Peng might correct if I am wrong, but yes, I believe this is correct. > > > > > Suggested-by: Ulf Hansson <ulf.hansson@linaro.org> > > Signed-off-by: Hiago De Franco <hiago.franco@toradex.com> > > --- > > 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 Thanks, I will correct this is next patch version. > > > + * > > + * @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. I believe this is correct, maybe Peng or Ulf can also comment here, but if that is the case then I can update the comment. > > 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 > > Best Regards, Hiago.
On Thu, 12 Jun 2025 at 19:31, Hiago De Franco <hiagofranco@gmail.com> wrote: > > On Wed, Jun 11, 2025 at 10:32:28AM -0500, Bjorn Andersson wrote: > > On Mon, Jun 02, 2025 at 10:19:03AM -0300, Hiago De Franco wrote: > > > From: Hiago De Franco <hiago.franco@toradex.com> > > > > > > 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? > > I am not fully familiar with the genpd's, so my knowledge might be > limited, but I think this is correct, if the genpd is shared. > > > > > > 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? > > Peng might correct if I am wrong, but yes, I believe this is correct. > > > > > > > > > Suggested-by: Ulf Hansson <ulf.hansson@linaro.org> > > > Signed-off-by: Hiago De Franco <hiago.franco@toradex.com> > > > --- > > > 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 > > Thanks, I will correct this is next patch version. > > > > > > + * > > > + * @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. > > I believe this is correct, maybe Peng or Ulf can also comment here, but > if that is the case then I can update the comment. Good point! I would not say that it's "dangerous", while I agree that we need to extend the comment to make it really clear that it returns the current power status of the genpd, which potentially may change beyond returning from the function and especially if the genpd has multiple consumers. [...] Kind regards Uffe
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 + * + * @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. + * + * 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