Re: [PATCH] PM: add dpm_use_runtime_{suspend, resume} helper functions

Alan Stern
2010-03-03T16:46:42Z

On Tue, 2 Mar 2010, Rafael J. Wysocki wrote:

> +/**
> + * __pm_generic_call - Generic suspend/freeze/poweroff/thaw subsystem callback.
> + * @dev: Device to handle.
> + * @event: PM transition of the system under way.
> + *
> + * If the device has not been suspended at run time, execute the
> + * suspend/freeze/poweroff/thaw callback provided by its driver, if defined, and
> + * return the error code returned by it. Otherwise, return zero.
> + */
> +static int __pm_generic_call(struct device *dev, int event)
> +{
> + const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
> + int (*callback)(struct device *);
> +
> + if (!pm || pm_runtime_suspended(dev))
> + return 0;
> +
> + switch (event) {
> + case PM_EVENT_SUSPEND:
> + callback = pm->suspend;
> + break;
> + case PM_EVENT_FREEZE:
> + callback = pm->freeze;
> + break;
> + case PM_EVENT_HIBERNATE:
> + callback = pm->poweroff;
> + break;
> + case PM_EVENT_THAW:
> + callback = pm->thaw;
> + break;
> + default:
> + callback = NULL;
> + break;
> + }
> +
> + return callback ? callback(dev) : 0;
> +}

Are you sure you want to avoid calling pm->thaw if the device is
runtime-suspended? Maybe it would be better to treat thaw like resume
or restore.

> --- linux-2.6.orig/include/linux/pm_runtime.h
> +++ linux-2.6/include/linux/pm_runtime.h
> @@ -62,6 +62,11 @@ static inline void device_set_run_wake(s
> dev->power.run_wake = enable;
> }
>
> +static inline bool pm_runtime_suspended(struct device *dev)
> +{
> + return dev->power.runtime_status == RPM_SUSPENDED;
> +}
> +

You didn't add this to the documentation file.

Alan Stern