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Wysocki" Cc: Linux PM , LKML , Alan Stern , Ulf Hansson , Wolfram Sang Subject: Re: [PATCH] PM: runtime: Add kerneldoc comments to multiple helpers Message-ID: <20200803230323.GA13316@paasikivi.fi.intel.com> References: <2672940.cHDmkauF2A@kreacher> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2672940.cHDmkauF2A@kreacher> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Rafael, One more comment below. On Fri, Jul 31, 2020 at 07:03:26PM +0200, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki > > Add kerneldoc comments to multiple PM-runtime helper functions > defined as static inline wrappers around lower-level routines to > provide quick reference decumentation of their behavior. > > Some of them are similar to each other with subtle differences only > and the behavior of some of them may appear as counter-intuitive, so > clarify all that to avoid confusion. > > Signed-off-by: Rafael J. Wysocki > --- > include/linux/pm_runtime.h | 246 +++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 246 insertions(+) > > Index: linux-pm/include/linux/pm_runtime.h > =================================================================== > --- linux-pm.orig/include/linux/pm_runtime.h > +++ linux-pm/include/linux/pm_runtime.h > @@ -60,58 +60,151 @@ extern void pm_runtime_put_suppliers(str > extern void pm_runtime_new_link(struct device *dev); > extern void pm_runtime_drop_link(struct device *dev); > > +/** > + * pm_runtime_get_if_in_use - Conditionally bump up runtime PM usage counter. > + * @dev: Target device. > + * > + * Increment the runtime PM usage counter of @dev if its runtime PM status is > + * %RPM_ACTIVE and its runtime PM usage counter is greater than 0. > + */ > static inline int pm_runtime_get_if_in_use(struct device *dev) > { > return pm_runtime_get_if_active(dev, false); > } > > +/** > + * pm_suspend_ignore_children - Set runtime PM behavior regarding children. > + * @dev: Target device. > + * @enable: Whether or not to ignore possible dependencies on children. > + * > + * The dependencies of @dev on its children will not be taken into account by > + * the runtime PM framework going forward if @enable is %true, or they will > + * be taken into account otherwise. > + */ > static inline void pm_suspend_ignore_children(struct device *dev, bool enable) > { > dev->power.ignore_children = enable; > } > > +/** > + * pm_runtime_get_noresume - Bump up runtime PM usage counter of a device. > + * @dev: Target device. > + */ > static inline void pm_runtime_get_noresume(struct device *dev) > { > atomic_inc(&dev->power.usage_count); > } > > +/** > + * pm_runtime_put_noidle - Drop runtime PM usage counter of a device. > + * @dev: Target device. > + * > + * Decrement the runtime PM usage counter of @dev unless it is 0 already. > + */ > static inline void pm_runtime_put_noidle(struct device *dev) > { > atomic_add_unless(&dev->power.usage_count, -1, 0); > } > > +/** > + * pm_runtime_suspended - Check whether or not a device is runtime-suspended. > + * @dev: Target device. > + * > + * Return %true if runtime PM is enabled for @dev and its runtime PM status is > + * %RPM_SUSPENDED, or %false otherwise. > + * > + * Note that the return value of this function can only be trusted if it is > + * called under the runtime PM lock of @dev or under conditions in which > + * runtime PM cannot be either disabled or enabled for @dev and its runtime PM > + * status cannot change. > + */ > static inline bool pm_runtime_suspended(struct device *dev) > { > return dev->power.runtime_status == RPM_SUSPENDED > && !dev->power.disable_depth; > } > > +/** > + * pm_runtime_active - Check whether or not a device is runtime-active. > + * @dev: Target device. > + * > + * Return %true if runtime PM is enabled for @dev and its runtime PM status is > + * %RPM_ACTIVE, or %false otherwise. > + * > + * Note that the return value of this function can only be trusted if it is > + * called under the runtime PM lock of @dev or under conditions in which > + * runtime PM cannot be either disabled or enabled for @dev and its runtime PM > + * status cannot change. > + */ > static inline bool pm_runtime_active(struct device *dev) > { > return dev->power.runtime_status == RPM_ACTIVE > || dev->power.disable_depth; > } > > +/** > + * pm_runtime_status_suspended - Check if runtime PM status is "suspended". > + * @dev: Target device. > + * > + * Return %true if the runtime PM status of @dev is %RPM_SUSPENDED, or %false > + * otherwise, regardless of whether or not runtime PM has been enabled for @dev. > + * > + * Note that the return value of this function can only be trusted if it is > + * called under the runtime PM lock of @dev or under conditions in which the > + * runtime PM status of @dev cannot change. > + */ > static inline bool pm_runtime_status_suspended(struct device *dev) > { > return dev->power.runtime_status == RPM_SUSPENDED; > } > > +/** > + * pm_runtime_enabled - Check if runtime PM is enabled. > + * @dev: Target device. > + * > + * Return %true if runtime PM is enabled for @dev or %false otherwise. > + * > + * Note that the return value of this function can only be trusted if it is > + * called under the runtime PM lock of @dev or under conditions in which > + * runtime PM cannot be either disabled or enabled for @dev. > + */ > static inline bool pm_runtime_enabled(struct device *dev) > { > return !dev->power.disable_depth; > } > > +/** > + * pm_runtime_has_no_callbacks - Check if runtime PM callbacks may be present. > + * @dev: Target device. > + * > + * Return %true if @dev is a special device without runtime PM callbacks or > + * %false otherwise. > + */ > static inline bool pm_runtime_has_no_callbacks(struct device *dev) > { > return dev->power.no_callbacks; > } > > +/** > + * pm_runtime_mark_last_busy - Update the last access time of a device. > + * @dev: Target device. > + * > + * Update the last access time of @dev used by the runtime PM autosuspend > + * mechanism to the current time as returned by ktime_get_mono_fast_ns(). > + */ > static inline void pm_runtime_mark_last_busy(struct device *dev) > { > WRITE_ONCE(dev->power.last_busy, ktime_get_mono_fast_ns()); > } > > +/** > + * pm_runtime_is_irq_safe - Check if runtime PM can work in interrupt context. > + * @dev: Target device. > + * > + * Return %true if @dev has been marked as an "IRQ-safe" device (with respect > + * to runtime PM), in which case its runtime PM callabcks can be expected to > + * work correctly when invoked from interrupt handlers. > + */ > static inline bool pm_runtime_is_irq_safe(struct device *dev) > { > return dev->power.irq_safe; > @@ -191,97 +284,250 @@ static inline void pm_runtime_drop_link( > > #endif /* !CONFIG_PM */ > > +/** > + * pm_runtime_idle - Conditionally set up autosuspend of a device or suspend it. > + * @dev: Target device. > + * > + * Invoke the "idle check" callback of @dev and, depending on its return value, > + * set up autosuspend of @dev or suspend it (depending on whether or not > + * autosuspend has been enabled for it). > + */ > static inline int pm_runtime_idle(struct device *dev) > { > return __pm_runtime_idle(dev, 0); > } > > +/** > + * pm_runtime_suspend - Suspend a device synchronously. > + * @dev: Target device. > + */ > static inline int pm_runtime_suspend(struct device *dev) > { > return __pm_runtime_suspend(dev, 0); > } > > +/** > + * pm_runtime_autosuspend - Set up autosuspend of a device or suspend it. > + * @dev: Target device. > + * > + * Set up autosuspend of @dev or suspend it (depending on whether or not > + * autosuspend is enabled for it) without engaging its "idle check" callback. > + */ > static inline int pm_runtime_autosuspend(struct device *dev) > { > return __pm_runtime_suspend(dev, RPM_AUTO); > } > > +/** > + * pm_runtime_resume - Resume a device synchronously. > + * @dev: Target device. > + */ > static inline int pm_runtime_resume(struct device *dev) > { > return __pm_runtime_resume(dev, 0); > } > > +/** > + * pm_request_idle - Queue up "idle check" execution for a device. > + * @dev: Target device. > + * > + * Queue up a work item to run an equivalent of pm_runtime_idle() for @dev > + * asynchronously. > + */ > static inline int pm_request_idle(struct device *dev) > { > return __pm_runtime_idle(dev, RPM_ASYNC); > } > > +/** > + * pm_request_resume - Queue up runtime-resume of a device. > + * @dev: Target device. > + */ > static inline int pm_request_resume(struct device *dev) > { > return __pm_runtime_resume(dev, RPM_ASYNC); > } > > +/** > + * pm_request_autosuspend - Queue up autosuspend of a device. > + * @dev: Target device. > + * > + * Queue up a work item to run an equivalent pm_runtime_autosuspend() for @dev > + * asynchronously. > + */ > static inline int pm_request_autosuspend(struct device *dev) > { > return __pm_runtime_suspend(dev, RPM_ASYNC | RPM_AUTO); > } > > +/** > + * pm_runtime_get - Bump up usage counter and queue up resume of a device. > + * @dev: Target device. > + * > + * Bump up the runtime PM usage counter of @dev and queue up a work item to > + * carry out runtime-resume of it. > + */ > static inline int pm_runtime_get(struct device *dev) > { > return __pm_runtime_resume(dev, RPM_GET_PUT | RPM_ASYNC); > } > > +/** > + * pm_runtime_get_sync - Bump up usage counter of a device and resume it. > + * @dev: Target device. > + * > + * Bump up the runtime PM usage counter of @dev and carry out runtime-resume of > + * it synchronously. > + * > + * The possible return values of this function are the same as for > + * pm_runtime_resume() and the runtime PM usage counter of @dev remains I think it's fine to refer to return values of pm_runtime_resume(), but the return values of pm_runtime_resume() are not documented above. Could you add them? Reviewed-by: Sakari Ailus -- Kind regards, Sakari Ailus