> The patch below introduces a mechanism allowing some devices to be
> resumed asynchronously, using completions with the following rules:
> (1) There is a completion, dev->power.comp, for each device object.
> (2) All of these completions are reset before suspend as well as
> each resume stage (dpm_resume_noirq(), dpm_resume()).
> (3) If dev->power.async_suspend is set for dev or for its parent, the
> PM core waits for the parent's completion before attempting to
> run the resume callbacks, appropriate for this particular stage
> of resume, for dev.
at least this needs to go in as a comment.
> (4) dev->power.comp is completed for each device after running its
> @@ -411,9 +412,12 @@ struct dev_pm_info {
> pm_message_t power_state;
> unsigned int can_wakeup:1;
> unsigned int should_wakeup:1;
> + unsigned async_suspend:1;
> enum dpm_state status; /* Owned by the PM core */
unsigned int? Or bool?
Should it go under config_pm_sleep?
> #ifdef CONFIG_PM_SLEEP
> struct list_head entry;
> + struct completion comp;
> + pm_message_t async_state;
> #endif
> }
>
> +static inline void device_enable_async_suspend(struct device *dev, bool enable)
> +{
> + if (dev->power.status == DPM_ON)
> + dev->power.async_suspend = enable;
> +}
> +
> @@ -163,6 +166,34 @@ void device_pm_move_last(struct device *
> list_move_tail(&dev->power.entry, &dpm_list);
> }
>
> +static void dpm_synchronize_noirq(void)
> +{
> + struct device *dev;
> +
> + async_synchronize_full();
> +
> + list_for_each_entry(dev, &dpm_list, power.entry)
> + INIT_COMPLETION(dev->power.comp);
> +}
> +
> +static void dpm_synchronize(void)
> +{
> + struct device *dev;
> +
> + async_synchronize_full();
> +
> + mutex_lock(&dpm_list_mtx);
> + list_for_each_entry(dev, &dpm_list, power.entry)
> + INIT_COMPLETION(dev->power.comp);
> + mutex_unlock(&dpm_list_mtx);
> +}
Why is it ok to avoid locking in noirq case? Do we really need async for
noirq handlers?
> /**
> - * device_resume_noirq - Power on one device (early resume).
> - * @dev: Device.
> - * @state: PM transition of the system being carried out.
> + * __device_resume_noirq - Execute an "early resume" callback for given device.
> + * @dev: Device to resume.
> + * @state: PM transition of the system being carried out.
> *
> - * Must be called with interrupts disabled.
> + * The driver of the device won't receive interrupts while this function is
> + * being executed.
> */
You still want it called with interrupts disabled, right?
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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