| Message ID | 8499566.e3riUpjlOo@vostro.rjw.lan (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 17 December 2015 at 02:54, Rafael J. Wysocki <rjw@rjwysocki.net> wrote: > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > Introduce a new runtime PM function, pm_runtime_get_if_in_use(), > that will increment the device's runtime PM usage counter and > return 'true' if its status is RPM_ACTIVE and its usage counter > is greater than 0 at the same time ('false' will be returned > otherwise). > > This is useful for things that should only be done if the device > is active (from the runtime PM perspective) and used by somebody > (as indicated by the usage counter) already and they are not worth > bothering otherwise. > > Requested-by: Imre Deak <imre.deak@intel.com> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Kind regards Uffe > --- > > Changes from v1: > - kerneldoc and runtime PM doc changes as suggested by Alan. > - The new function returns an int now and -EINVAL is returned for devices > with runtime PM disabled. > > --- > Documentation/power/runtime_pm.txt | 6 ++++++ > drivers/base/power/runtime.c | 24 ++++++++++++++++++++++++ > include/linux/pm_runtime.h | 5 +++++ > 3 files changed, 35 insertions(+) > > Index: linux-pm/drivers/base/power/runtime.c > =================================================================== > --- linux-pm.orig/drivers/base/power/runtime.c > +++ linux-pm/drivers/base/power/runtime.c > @@ -966,6 +966,30 @@ int __pm_runtime_resume(struct device *d > EXPORT_SYMBOL_GPL(__pm_runtime_resume); > > /** > + * pm_runtime_get_if_in_use - Conditionally bump up the device's usage counter. > + * @dev: Device to handle. > + * > + * Return -EINVAL if runtime PM is disabled for the device. > + * > + * If that's not the case and if the device's runtime PM status is RPM_ACTIVE > + * and the runtime PM usage counter is nonzero, increment the counter and > + * return 1. Otherwise return 0 without changing the counter. > + */ > +int pm_runtime_get_if_in_use(struct device *dev) > +{ > + unsigned long flags; > + int retval; > + > + spin_lock_irqsave(&dev->power.lock, flags); > + retval = dev->power.disable_depth > 0 ? -EINVAL : > + dev->power.runtime_status == RPM_ACTIVE > + && atomic_inc_not_zero(&dev->power.usage_count); > + spin_unlock_irqrestore(&dev->power.lock, flags); > + return retval; > +} > +EXPORT_SYMBOL_GPL(pm_runtime_get_if_in_use); > + > +/** > * __pm_runtime_set_status - Set runtime PM status of a device. > * @dev: Device to handle. > * @status: New runtime PM status of the device. > Index: linux-pm/include/linux/pm_runtime.h > =================================================================== > --- linux-pm.orig/include/linux/pm_runtime.h > +++ linux-pm/include/linux/pm_runtime.h > @@ -39,6 +39,7 @@ extern int pm_runtime_force_resume(struc > extern int __pm_runtime_idle(struct device *dev, int rpmflags); > extern int __pm_runtime_suspend(struct device *dev, int rpmflags); > extern int __pm_runtime_resume(struct device *dev, int rpmflags); > +extern int pm_runtime_get_if_in_use(struct device *dev); > extern int pm_schedule_suspend(struct device *dev, unsigned int delay); > extern int __pm_runtime_set_status(struct device *dev, unsigned int status); > extern int pm_runtime_barrier(struct device *dev); > @@ -143,6 +144,10 @@ static inline int pm_schedule_suspend(st > { > return -ENOSYS; > } > +static inline int pm_runtime_get_if_in_use(struct device *dev) > +{ > + return -EINVAL; > +} > static inline int __pm_runtime_set_status(struct device *dev, > unsigned int status) { return 0; } > static inline int pm_runtime_barrier(struct device *dev) { return 0; } > Index: linux-pm/Documentation/power/runtime_pm.txt > =================================================================== > --- linux-pm.orig/Documentation/power/runtime_pm.txt > +++ linux-pm/Documentation/power/runtime_pm.txt > @@ -371,6 +371,12 @@ drivers/base/power/runtime.c and include > - increment the device's usage counter, run pm_runtime_resume(dev) and > return its result > > + int pm_runtime_get_if_in_use(struct device *dev); > + - return -EINVAL if 'power.disable_depth' is nonzero; otherwise, if the > + runtime PM status is RPM_ACTIVE and the runtime PM usage counter is > + nonzero, increment the counter and return 1; otherwise return 0 without > + changing the counter > + > void pm_runtime_put_noidle(struct device *dev); > - decrement the device's usage counter > >
Index: linux-pm/drivers/base/power/runtime.c =================================================================== --- linux-pm.orig/drivers/base/power/runtime.c +++ linux-pm/drivers/base/power/runtime.c @@ -966,6 +966,30 @@ int __pm_runtime_resume(struct device *d EXPORT_SYMBOL_GPL(__pm_runtime_resume); /** + * pm_runtime_get_if_in_use - Conditionally bump up the device's usage counter. + * @dev: Device to handle. + * + * Return -EINVAL if runtime PM is disabled for the device. + * + * If that's not the case and if the device's runtime PM status is RPM_ACTIVE + * and the runtime PM usage counter is nonzero, increment the counter and + * return 1. Otherwise return 0 without changing the counter. + */ +int pm_runtime_get_if_in_use(struct device *dev) +{ + unsigned long flags; + int retval; + + spin_lock_irqsave(&dev->power.lock, flags); + retval = dev->power.disable_depth > 0 ? -EINVAL : + dev->power.runtime_status == RPM_ACTIVE + && atomic_inc_not_zero(&dev->power.usage_count); + spin_unlock_irqrestore(&dev->power.lock, flags); + return retval; +} +EXPORT_SYMBOL_GPL(pm_runtime_get_if_in_use); + +/** * __pm_runtime_set_status - Set runtime PM status of a device. * @dev: Device to handle. * @status: New runtime PM status of the device. Index: linux-pm/include/linux/pm_runtime.h =================================================================== --- linux-pm.orig/include/linux/pm_runtime.h +++ linux-pm/include/linux/pm_runtime.h @@ -39,6 +39,7 @@ extern int pm_runtime_force_resume(struc extern int __pm_runtime_idle(struct device *dev, int rpmflags); extern int __pm_runtime_suspend(struct device *dev, int rpmflags); extern int __pm_runtime_resume(struct device *dev, int rpmflags); +extern int pm_runtime_get_if_in_use(struct device *dev); extern int pm_schedule_suspend(struct device *dev, unsigned int delay); extern int __pm_runtime_set_status(struct device *dev, unsigned int status); extern int pm_runtime_barrier(struct device *dev); @@ -143,6 +144,10 @@ static inline int pm_schedule_suspend(st { return -ENOSYS; } +static inline int pm_runtime_get_if_in_use(struct device *dev) +{ + return -EINVAL; +} static inline int __pm_runtime_set_status(struct device *dev, unsigned int status) { return 0; } static inline int pm_runtime_barrier(struct device *dev) { return 0; } Index: linux-pm/Documentation/power/runtime_pm.txt =================================================================== --- linux-pm.orig/Documentation/power/runtime_pm.txt +++ linux-pm/Documentation/power/runtime_pm.txt @@ -371,6 +371,12 @@ drivers/base/power/runtime.c and include - increment the device's usage counter, run pm_runtime_resume(dev) and return its result + int pm_runtime_get_if_in_use(struct device *dev); + - return -EINVAL if 'power.disable_depth' is nonzero; otherwise, if the + runtime PM status is RPM_ACTIVE and the runtime PM usage counter is + nonzero, increment the counter and return 1; otherwise return 0 without + changing the counter + void pm_runtime_put_noidle(struct device *dev); - decrement the device's usage counter