Messages in this thread | | | From | Oliver Neukum <> | Subject | Re: [linux-pm] Run-time PM idea (was: Re: [RFC][PATCH 0/2] PM: Rearrange core suspend code) | Date | Mon, 8 Jun 2009 14:04:03 +0200 |
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Am Montag, 8. Juni 2009 13:29:26 schrieb Rafael J. Wysocki:
> But I need to be able to call __pm_schedule_resume() (at least) from > interrupt context and I can't use a mutex from there. Otherwise I'd have > used a mutex. :-)
I see.
> Anyway, below is a version with synchronous resume.
You are assuming autosuspend should always be with a delay. Why?
Secondly, you are not using a counter. Therefore only one driver can control the PM state of a device at a given time. Is that wise?
> + * __pm_schedule_suspend - Schedule run-time suspend of given device. > + * @dev: Device to suspend. > + * @delay: Time to wait before attempting to suspend the device.
In which unit of time? If this is to go into kerneldoc that must be specified.
> + * @autocancel: If set, the request will be cancelled during a resume from > a + * system-wide sleep state if it happens before @delay elapses.
Why is this needed?
> + */ > +void __pm_schedule_suspend(struct device *dev, unsigned long delay, > + bool autocancel)
[..]
> + > +/** > + * __pm_schedule_resume - Schedule run-time resume of given device. > + * @dev: Device to resume. > + * @autocancel: If set, the request will be cancelled during a resume from > a + * system-wide sleep state if it happens before pm_autoresume() can be > run. + */
Eeek! This is a bad idea. You never want to a resume to be cancelled.
> +void __pm_schedule_resume(struct device *dev, bool autocancel)
[..] > +int pm_resume_sync(struct device *dev) > +{ > + int error = 0; > + > + pm_lock_device(dev); > + if (dev->power.runtime_status == RPM_IDLE) { > + /* ->autosuspend() hasn't started yet, no need to resume. */ > + pm_cancel_suspend(dev); > + goto out; > + } > + > + if (dev->power.runtime_status == RPM_SUSPENDING) { > + /* > + * The ->autosuspend() callback is being executed right now, > + * wait for it to complete. > + */ > + pm_unlock_device(dev); > + cancel_delayed_work_sync(&dev->power.suspend_work);
That is the most glorious abuse of an API I've seen this year :-)
Regards Oliver
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