Commit b3db492e authored by Sakari Ailus's avatar Sakari Ailus Committed by Rafael J. Wysocki
Browse files

PM: runtime: Mark last busy stamp in pm_runtime_put_autosuspend() 



Set device's last busy timestamp to current time in
pm_runtime_put_autosuspend(). Callers wishing not to do that will need to
use __pm_runtime_put_autosuspend().

Signed-off-by: default avatarSakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patch.msgid.link/20250616061212.2286741-3-sakari.ailus@linux.intel.com


Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 271ff96d

Documentation/power/runtime_pm.rst

+10 −13
Original line number Diff line number Diff line
@@ -411,8 +411,9 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h: 
      pm_request_idle(dev) and return its result



  `int pm_runtime_put_autosuspend(struct device *dev);`

    - does the same as __pm_runtime_put_autosuspend() for now, but in the

      future, will also call pm_runtime_mark_last_busy() as well, DO NOT USE!

    - set the power.last_busy field to the current time and decrement the

      device's usage counter; if the result is 0 then run

      pm_request_autosuspend(dev) and return its result



  `int __pm_runtime_put_autosuspend(struct device *dev);`

    - decrement the device's usage counter; if the result is 0 then run
@@ -870,11 +871,9 @@ device is automatically suspended (the subsystem or driver still has to call 
the appropriate PM routines); rather it means that runtime suspends will

automatically be delayed until the desired period of inactivity has elapsed.



Inactivity is determined based on the power.last_busy field.  Drivers should

call pm_runtime_mark_last_busy() to update this field after carrying out I/O,

typically just before calling __pm_runtime_put_autosuspend().  The desired

length of the inactivity period is a matter of policy.  Subsystems can set this

length initially by calling pm_runtime_set_autosuspend_delay(), but after device

Inactivity is determined based on the power.last_busy field. The desired length

of the inactivity period is a matter of policy.  Subsystems can set this length

initially by calling pm_runtime_set_autosuspend_delay(), but after device

registration the length should be controlled by user space, using the

/sys/devices/.../power/autosuspend_delay_ms attribute.
@@ -885,7 +884,7 @@ instead of the non-autosuspend counterparts:: 


	Instead of: pm_runtime_suspend    use: pm_runtime_autosuspend;

	Instead of: pm_schedule_suspend   use: pm_request_autosuspend;

	Instead of: pm_runtime_put        use: __pm_runtime_put_autosuspend;

	Instead of: pm_runtime_put        use: pm_runtime_put_autosuspend;

	Instead of: pm_runtime_put_sync   use: pm_runtime_put_sync_autosuspend.



Drivers may also continue to use the non-autosuspend helper functions; they
@@ -922,12 +921,10 @@ Here is a schematic pseudo-code example:: 
	foo_io_completion(struct foo_priv *foo, void *req)

	{

		lock(&foo->private_lock);

		if (--foo->num_pending_requests == 0) {

			pm_runtime_mark_last_busy(&foo->dev);

			__pm_runtime_put_autosuspend(&foo->dev);

		} else {

		if (--foo->num_pending_requests == 0)

			pm_runtime_put_autosuspend(&foo->dev);

		else

			foo_process_next_request(foo);

		}

		unlock(&foo->private_lock);

		/* Send req result back to the user ... */

	}

include/linux/pm_runtime.h

+7 −5
Original line number Diff line number Diff line
@@ -568,11 +568,13 @@ static inline int __pm_runtime_put_autosuspend(struct device *dev) 
}



/**

 * pm_runtime_put_autosuspend - Drop device usage counter and queue autosuspend if 0.

 * pm_runtime_put_autosuspend - Update the last access time of a device, drop

 * its usage counter and queue autosuspend if the usage counter becomes 0.

 * @dev: Target device.

 *

 * Decrement the runtime PM usage counter of @dev and if it turns out to be

 * equal to 0, queue up a work item for @dev like in pm_request_autosuspend().

 * Update the last access time of @dev, decrement runtime PM usage counter of

 * @dev and if it turns out to be equal to 0, queue up a work item for @dev like

 * in pm_request_autosuspend().

 *

 * Return:

 * * 0: Success.
@@ -587,8 +589,8 @@ static inline int __pm_runtime_put_autosuspend(struct device *dev) 
 */

static inline int pm_runtime_put_autosuspend(struct device *dev)

{

	return __pm_runtime_suspend(dev,

	    RPM_GET_PUT | RPM_ASYNC | RPM_AUTO);

	pm_runtime_mark_last_busy(dev);

	return __pm_runtime_put_autosuspend(dev);

}



/**