Re: [PATCH 2/2] iio: adc: ti-ads8688: fix timestamp is not updated in buffer

[Jonathan Cameron <jic23@kernel.org>]

On Tue,  7 May 2019 10:23:04 +0200
Sean Nyekjaer <sean@geanix.com> wrote:

> When using the hrtimer iio trigger timestamp isn't updated.
> If we use iio_get_time_ns it is updated correctly.
> 
> Fixes: 2a86487786b5c ("iio: adc: ti-ads8688: add trigger and buffer support")
> Signed-off-by: Sean Nyekjaer <sean@geanix.com>
Ah. I assumed this was the normal, with interrupts it'll update, with hrtimer
it won't - but turns out that in this driver it isn't updated in any path as
the top half that sets pf->timestamp isn't being registered.

Not registering that is correct for a device that doesn't have a dataready interrupt
as we want the timestamp as near to the actual read time as possible.

Applied to the fixes-togreg branch of iio.git and marked for stable.

Thanks,

Jonathan

> ---
>  drivers/iio/adc/ti-ads8688.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/iio/adc/ti-ads8688.c b/drivers/iio/adc/ti-ads8688.c
> index d9c354dbd7e4..304cad3dddc6 100644
> --- a/drivers/iio/adc/ti-ads8688.c
> +++ b/drivers/iio/adc/ti-ads8688.c
> @@ -396,7 +396,7 @@ static irqreturn_t ads8688_trigger_handler(int irq, void *p)
>  	}
>  
>  	iio_push_to_buffers_with_timestamp(indio_dev, buffer,
> -			pf->timestamp);
> +			iio_get_time_ns(indio_dev));
>  
>  	iio_trigger_notify_done(indio_dev->trig);
>