From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joonas Lahtinen Subject: Re: [PATCH] PM / runtime: Add new helper for conditional usage count incrementation Date: Tue, 15 Dec 2015 12:21:06 +0200 Message-ID: <1450174866.9206.1.camel@linux.intel.com> References: <1449675920-12986-1-git-send-email-joonas.lahtinen@linux.intel.com> <1449949245.2815.20.camel@intel.com> <20151212194956.GA2407@nuc-i3427.alporthouse.com> <32970649.AWpGt5zezN@vostro.rjw.lan> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <32970649.AWpGt5zezN@vostro.rjw.lan> Sender: linux-pm-owner@vger.kernel.org To: "Rafael J. Wysocki" , Chris Wilson , Imre Deak Cc: Intel graphics driver community testing & development , linux-pm@vger.kernel.org List-Id: intel-gfx@lists.freedesktop.org On ma, 2015-12-14 at 23:22 +0100, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki > > 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 > Acked-by: Imre Deak Reviewed-by: Joonas Lahtinen > Signed-off-by: Rafael J. Wysocki > --- > Documentation/power/runtime_pm.txt | 5 +++++ > drivers/base/power/runtime.c | 21 +++++++++++++++++++++ > include/linux/pm_runtime.h | 5 +++++ > 3 files changed, 31 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 +966,27 @@ 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. > + * > + * Increment the device's runtime PM usage counter and return 'true' > if its > + * runtime PM status is RPM_ACTIVE and its usage counter is already > different > + * from zero at the same time. Otherwise, return 'false'. > + */ > +bool pm_runtime_get_if_in_use(struct device *dev) > +{ > + unsigned long flags; > + bool retval; > + > + spin_lock_irqsave(&dev->power.lock, flags); > + retval = 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 bool 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 bool pm_runtime_get_if_in_use(struct device *dev) > +{ > + return true; > +} > 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 +371,11 @@ drivers/base/power/runtime.c and include > - increment the device's usage counter, run > pm_runtime_resume(dev) and > return its result > > + bool pm_runtime_get_if_in_use(struct device *dev); > + - increment the device's usage counter and return 'true' if its > runtime PM > + status is 'active' and its usage counter is greater than 0 at > the same > + time; return 'false' otherwise > + > void pm_runtime_put_noidle(struct device *dev); > - decrement the device's usage counter > > -- Joonas Lahtinen Open Source Technology Center Intel Corporation