Re: [PATCH 3/4] iio: hid-sensor-temperature: Fix issues of timestamp channel

[Jonathan Cameron <jic23@kernel.org>]

On Wed,  3 Mar 2021 14:36:14 +0800
Ye Xiang <xiang.ye@intel.com> wrote:

> This patch fixes 2 issues of timestamp channel:
> 1. This patch ensures that there is sufficient space and correct
> alignment for the timestamp.
> 2. Correct the timestamp channel scan index.
This isn't technically a bug because channel index numbers just need
to be monotonic.  Still it's a reasonable tidy up given 1.
> 
> Fixes: 59d0f2da3569 ("iio: hid: Add temperature sensor support")
> Signed-off-by: Ye Xiang <xiang.ye@intel.com>
Applied to the fixes togreg branch of iio.git and marked for stable.
Patch 4 is not a fix (I think) so will have to wait for this to
be upstream.

Jonathan

> ---
>  drivers/iio/temperature/hid-sensor-temperature.c | 14 ++++++++------
>  1 file changed, 8 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/iio/temperature/hid-sensor-temperature.c b/drivers/iio/temperature/hid-sensor-temperature.c
> index e3d38cbcf354..dc534ed784c3 100644
> --- a/drivers/iio/temperature/hid-sensor-temperature.c
> +++ b/drivers/iio/temperature/hid-sensor-temperature.c
> @@ -15,7 +15,10 @@
>  struct temperature_state {
>  	struct hid_sensor_common common_attributes;
>  	struct hid_sensor_hub_attribute_info temperature_attr;
> -	s32 temperature_data;
> +	struct {
> +		s32 temperature_data;
> +		u64 timestamp __aligned(8);
> +	} scan;
>  	int scale_pre_decml;
>  	int scale_post_decml;
>  	int scale_precision;
> @@ -36,7 +39,7 @@ static const struct iio_chan_spec temperature_channels[] = {
>  			BIT(IIO_CHAN_INFO_SAMP_FREQ) |
>  			BIT(IIO_CHAN_INFO_HYSTERESIS),
>  	},
> -	IIO_CHAN_SOFT_TIMESTAMP(3),
> +	IIO_CHAN_SOFT_TIMESTAMP(1),
>  };
>  
>  /* Adjust channel real bits based on report descriptor */
> @@ -127,9 +130,8 @@ static int temperature_proc_event(struct hid_sensor_hub_device *hsdev,
>  	struct temperature_state *temp_st = iio_priv(indio_dev);
>  
>  	if (atomic_read(&temp_st->common_attributes.data_ready))
> -		iio_push_to_buffers_with_timestamp(indio_dev,
> -				&temp_st->temperature_data,
> -				iio_get_time_ns(indio_dev));
> +		iio_push_to_buffers_with_timestamp(indio_dev, &temp_st->scan,
> +						   iio_get_time_ns(indio_dev));
>  
>  	return 0;
>  }
> @@ -144,7 +146,7 @@ static int temperature_capture_sample(struct hid_sensor_hub_device *hsdev,
>  
>  	switch (usage_id) {
>  	case HID_USAGE_SENSOR_DATA_ENVIRONMENTAL_TEMPERATURE:
> -		temp_st->temperature_data = *(s32 *)raw_data;
> +		temp_st->scan.temperature_data = *(s32 *)raw_data;
>  		return 0;
>  	default:
>  		return -EINVAL;