On Tuesday, January 14, 2014 03:18:08 PM Chuansheng Liu wrote:
>
> Currently, the dpm_resume_noirq() is done synchronously, and for PCI devices
> pci_pm_resume_noirq():
>
> pci_pm_resume_noirq()
> pci_pm_default_resume_early()
> pci_power_up()
> pci_raw_set_power_state()
> Which set the device from D3hot to D0 mostly, for every device, there will
> be one 10ms(pci_pm_d3_delay) to wait.
>
> Hence normally dpm_resume_noirq() will cost > 100ms, which is bigger for
> mobile
> platform.
pci_pm_d3_delay usually is not 10 ms. What is 10 ms is dev->d3_delay, but
that also is not on every platform now.
That said the approach here makes sense, but I have two questions:
1. On what systems has it been tested?
2. What about suspend_late/resume_early? If the _noirq things are to be
executed
asynchronously, those should be too.
Thanks!
> Here implementing it with asynchronous way which will reduce much.
>
> For example below, The 80% time is saved.
> With synchronous way:
> [ 1411.272218] PM: noirq resume of devices complete after 92.223 msecs
> With asynchronous way:
> [ 110.616735] PM: noirq resume of devices complete after 10.544 msecs
>
> Signed-off-by: Liu, Chuansheng <chuansheng....@intel.com>
> ---
> drivers/base/power/main.c | 42 +++++++++++++++++++++++++++++++++---------
> 1 file changed, 33 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
> index 1b41fca..1b9d774 100644
> --- a/drivers/base/power/main.c
> +++ b/drivers/base/power/main.c
> @@ -505,6 +505,19 @@ static int device_resume_noirq(struct device *dev,
> pm_message_t state)
> return error;
> }
>
> +static bool is_async(struct device *dev);
> +
> +static void async_resume_noirq(void *data, async_cookie_t cookie)
> +{
> + struct device *dev = (struct device *)data;
> + int error;
> +
> + error = device_resume_noirq(dev, pm_transition);
> + if (error)
> + pm_dev_err(dev, pm_transition, " noirq", error);
> + put_device(dev);
> +}
> +
> /**
> * dpm_resume_noirq - Execute "noirq resume" callbacks for all devices.
> * @state: PM transition of the system being carried out.
> @@ -514,29 +527,40 @@ static int device_resume_noirq(struct device *dev,
> pm_message_t state)
> */
> static void dpm_resume_noirq(pm_message_t state)
> {
> + struct device *dev;
> ktime_t starttime = ktime_get();
> + pm_transition = state;
> +
> + list_for_each_entry(dev, &dpm_noirq_list, power.entry) {
> + if (is_async(dev)) {
> + get_device(dev);
> + async_schedule(async_resume_noirq, dev);
> + }
> + }
>
> mutex_lock(&dpm_list_mtx);
> while (!list_empty(&dpm_noirq_list)) {
> - struct device *dev = to_device(dpm_noirq_list.next);
> - int error;
> + dev = to_device(dpm_noirq_list.next);
>
> get_device(dev);
> list_move_tail(&dev->power.entry, &dpm_late_early_list);
> mutex_unlock(&dpm_list_mtx);
>
> - error = device_resume_noirq(dev, state);
> - if (error) {
> - suspend_stats.failed_resume_noirq++;
> - dpm_save_failed_step(SUSPEND_RESUME_NOIRQ);
> - dpm_save_failed_dev(dev_name(dev));
> - pm_dev_err(dev, state, " noirq", error);
> + if (!is_async(dev)) {
> + int error;
> + error = device_resume_noirq(dev, state);
> + if (error) {
> + suspend_stats.failed_resume_noirq++;
> + dpm_save_failed_step(SUSPEND_RESUME_NOIRQ);
> + dpm_save_failed_dev(dev_name(dev));
> + pm_dev_err(dev, state, " noirq", error);
> + }
> }
> -
> mutex_lock(&dpm_list_mtx);
> put_device(dev);
> }
> mutex_unlock(&dpm_list_mtx);
> + async_synchronize_full();
> dpm_show_time(starttime, state, "noirq");
> resume_device_irqs();
> cpuidle_resume();
>
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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