Re: [PATCH 04/15] iio: accel: adxl380: don't stay in standby on -EINVAL

["Nuno Sá" <nuno.sa@analog.com>]

On Tue, Oct 27, 2026 at 05:19:08PM +0100, Greg Kroah-Hartman wrote:
> From: Josef Bacik <josef@toxicpanda.com>
> 
> adxl380_set_act_inact_threshold() puts the sensor into standby, writes the
> threshold and switches the measurement on again.  A threshold above 8191 is
> refused in between, and the sensor stays in standby: no samples and no
> events until the next write that succeeds.
> 
> adxl380_set_range() has the same problem and a worse one.  It rescales both
> thresholds for the new range.  If one no longer fits it returns -EINVAL
> with the sensor in standby, the new range in the chip, the old one in
> st->range and rescaled thresholds in the driver's state: from the next
> successful write on the samples are reported with the wrong scale.
> 
> Switch the measurement on again if the threshold is refused.  In
> adxl380_set_range() see whether the thresholds fit before anything is
> changed.
> 
> Fixes: df36de13677a ("iio: accel: add ADXL380 driver")
> Cc: stable <stable@kernel.org>
> Cc: Ramona Gradinariu <ramona.gradinariu@analog.com>
> Cc: Antoniu Miclaus <antoniu.miclaus@analog.com>
> Cc: "Nuno Sá" <nuno.sa@analog.com>
> Cc: Michael Hennerich <Michael.Hennerich@analog.com>
> Cc: David Lechner <dlechner@baylibre.com>
> Cc: Andy Shevchenko <andy@kernel.org>
> Signed-off-by: Josef Bacik <josef@toxicpanda.com>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> ---

Reviewed-by: Nuno Sá <nuno.sa@analog.com>

>  drivers/iio/accel/adxl380.c | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/iio/accel/adxl380.c b/drivers/iio/accel/adxl380.c
> index 8518ee23e114..03b140303520 100644
> --- a/drivers/iio/accel/adxl380.c
> +++ b/drivers/iio/accel/adxl380.c
> @@ -334,8 +334,11 @@ static int adxl380_set_act_inact_threshold(struct iio_dev *indio_dev,
>  		return ret;
>  
>  	ret = adxl380_write_act_inact_threshold(st, act, th);
> -	if (ret)
> +	if (ret) {
> +		/* Leave standby also if the value was refused */
> +		adxl380_set_measure_en(st, true);
>  		return ret;
> +	}
>  
>  	return adxl380_set_measure_en(st, true);
>  }
> @@ -698,6 +701,12 @@ static int adxl380_set_range(struct adxl380_state *st, u8 range)
>  
>  	guard(mutex)(&st->lock);
>  
> +	/* The thresholds are rescaled: see that they fit before any change */
> +	if (mult_frac(max(st->act_threshold, st->inact_threshold),
> +		      adxl380_range_scale_factor_tbl[st->range],
> +		      adxl380_range_scale_factor_tbl[range]) > ADXL380_THRESH_MAX)
> +		return -EINVAL;
> +
>  	ret = adxl380_set_measure_en(st, false);
>  	if (ret)
>  		return ret;
> 
> -- 
> 2.56.0
>