Re: [PATCH] iio: hid-sensor-trigger: Change get poll value function order to avoid sensor properties losing after resume from S3

["Pandruvada, Srinivas" <srinivas.pandruvada-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>]

On Wed, 2017-02-22 at 17:17 +0800, Song Hongyan wrote:
> In function _hid_sensor_power_state(), when
> hid_sensor_read_poll_value()
> is called, sensor's all properties will be updated by the value from
> sensor hardware/firmware.
> In some implementation, sensor hardware/firmware will do a power
> cycle
> during S3. In this case, after resume, once
> hid_sensor_read_poll_value()
> is called, sensor's all properties which are kept by driver during S3
> will be changed to default value.
> But instead, if a set feature function is called first, sensor
> hardware/firmware will be recovered to the last status. So change the
> sensor_hub_set_feature() calling order to behind of set feature
> function
> to avoid sensor properties lose.
> 
> Signed-off-by: Song Hongyan <hongyan.song@intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

> ---
>  drivers/iio/common/hid-sensors/hid-sensor-trigger.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/iio/common/hid-sensors/hid-sensor-trigger.c
> b/drivers/iio/common/hid-sensors/hid-sensor-trigger.c
> index a3cce3a..ecf592d 100644
> --- a/drivers/iio/common/hid-sensors/hid-sensor-trigger.c
> +++ b/drivers/iio/common/hid-sensors/hid-sensor-trigger.c
> @@ -51,8 +51,6 @@ static int _hid_sensor_power_state(struct
> hid_sensor_common *st, bool state)
>  			st->report_state.report_id,
>  			st->report_state.index,
>  			HID_USAGE_SENSOR_PROP_REPORTING_STATE_ALL_EV
> ENTS_ENUM);
> -
> -		poll_value = hid_sensor_read_poll_value(st);
>  	} else {
>  		int val;
>  
> @@ -89,7 +87,9 @@ static int _hid_sensor_power_state(struct
> hid_sensor_common *st, bool state)
>  	sensor_hub_get_feature(st->hsdev, st->power_state.report_id,
>  			       st->power_state.index,
>  			       sizeof(state_val), &state_val);
> -	if (state && poll_value)
> +	if (state)
> +		poll_value = hid_sensor_read_poll_value(st);
> +	if (poll_value > 0)
>  		msleep_interruptible(poll_value * 2);
>  
>  	return 0;