On Sun, 2015-05-17 at 09:22 +0100, Jonathan Cameron wrote:
> On 15/05/15 18:40, Srinivas Pandruvada wrote:
> > When system suspend is issued, the pm core issues resume call for all
> > run time suspended devices. This is required for some devices to
> > continue suspend.
> > For sensor hub we don't need to runtime resume devices and then suspend.
> > So when the system suspend is in progress, ignore call to power up
> > the sensors. This has a significant impact on suspend/resume performance.
> >
> > Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
> Hi Srinivas,
Hi Jonathan,
>
> This isn't an area I know much about and am a little unlikely to get time to
> dig into in the next few days. A quick grep didn't throw up lots of other
> drivers doing this, so is there precedence somewhere?
>
We are trying trying to submit patch for similar for usb xhci, which has
the same issue with the delay.
Let me check with Rafael to see if I have some better option. May be we
need some support in PM core.
Thanks,
Srinivas
> Jonathan
> > ---
> > .../iio/common/hid-sensors/hid-sensor-trigger.c | 31 ++++++++++++++++++++++
> > include/linux/hid-sensor-hub.h | 2 ++
> > 2 files changed, 33 insertions(+)
> >
> > diff --git a/drivers/iio/common/hid-sensors/hid-sensor-trigger.c b/drivers/iio/common/hid-sensors/hid-sensor-trigger.c
> > index 610fc98..d9170d2 100644
> > --- a/drivers/iio/common/hid-sensors/hid-sensor-trigger.c
> > +++ b/drivers/iio/common/hid-sensors/hid-sensor-trigger.c
> > @@ -23,6 +23,7 @@
> > #include <linux/irq.h>
> > #include <linux/slab.h>
> > #include <linux/delay.h>
> > +#include <linux/suspend.h>
> > #include <linux/hid-sensor-hub.h>
> > #include <linux/iio/iio.h>
> > #include <linux/iio/trigger.h>
> > @@ -36,6 +37,9 @@ static int _hid_sensor_power_state(struct hid_sensor_common *st, bool state)
> > s32 poll_value = 0;
> >
> > if (state) {
> > + if (atomic_read(&st->suspend_in_progress))
> > + return 0;
> > +
> > if (sensor_hub_device_open(st->hsdev))
> > return -EIO;
> >
> > @@ -113,6 +117,28 @@ int hid_sensor_power_state(struct hid_sensor_common *st, bool state)
> > #endif
> > }
> >
> > +static int hid_sensor_pm_notifier(struct notifier_block *nb, unsigned long val,
> > + void *ptr)
> > +{
> > + struct hid_sensor_common *common =
> > + container_of(nb, struct hid_sensor_common, pm_nb);
> > +
> > + switch (val) {
> > + case PM_HIBERNATION_PREPARE:
> > + case PM_SUSPEND_PREPARE:
> > + atomic_set(&common->suspend_in_progress, 1);
> > + break;
> > + case PM_POST_HIBERNATION:
> > + case PM_POST_SUSPEND:
> > + case PM_POST_RESTORE:
> > + atomic_set(&common->suspend_in_progress, 0);
> > + break;
> > + default:
> > + break;
> > + }
> > + return 0;
> > +}
> > +
> > static int hid_sensor_data_rdy_trigger_set_state(struct iio_trigger *trig,
> > bool state)
> > {
> > @@ -121,6 +147,7 @@ static int hid_sensor_data_rdy_trigger_set_state(struct iio_trigger *trig,
> >
> > void hid_sensor_remove_trigger(struct hid_sensor_common *attrb)
> > {
> > + unregister_pm_notifier(&attrb->pm_nb);
> > iio_trigger_unregister(attrb->trigger);
> > iio_trigger_free(attrb->trigger);
> > }
> > @@ -168,6 +195,10 @@ int hid_sensor_setup_trigger(struct iio_dev *indio_dev, const char *name,
> > 3000);
> > pm_runtime_use_autosuspend(&attrb->pdev->dev);
> >
> > + atomic_set(&attrb->suspend_in_progress, 0);
> > + attrb->pm_nb.notifier_call = hid_sensor_pm_notifier;
> > + register_pm_notifier(&attrb->pm_nb);
> > +
> > return ret;
> > error_unreg_trigger:
> > iio_trigger_unregister(trig);
> > diff --git a/include/linux/hid-sensor-hub.h b/include/linux/hid-sensor-hub.h
> > index 0042bf3..e38c72a 100644
> > --- a/include/linux/hid-sensor-hub.h
> > +++ b/include/linux/hid-sensor-hub.h
> > @@ -230,6 +230,8 @@ struct hid_sensor_common {
> > struct platform_device *pdev;
> > unsigned usage_id;
> > atomic_t data_ready;
> > + atomic_t suspend_in_progress;
> > + struct notifier_block pm_nb;
> > struct iio_trigger *trigger;
> > struct hid_sensor_hub_attribute_info poll;
> > struct hid_sensor_hub_attribute_info report_state;
> >
>
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