On Mon, 2015-05-18 at 08:25 -0700, Srinivas Pandruvada wrote:
> 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?
> >
There are some issue in Linux PM domain, which prevents using some
mechanism to prevent runtime resume and regular resume for this device.
Also since iio devices has trigger devices as children which don't have
PM callbacks, the PM core resets some flags.
I am working with Rafael to address issues in core first, then I can
come up with some alternative solution.
Thanks,
Srinivas
> 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;
> > >
> >
>
��.n��������+%������w��{.n�����{��(��)�� jg��� �����ݢj����G���� ���j:+v���w�m������w�������h�����٥
