Commit be2b89a9 authored Jan 08, 2022 by Liam Beguin Committed by Greg Kroah-Hartman Apr 15, 2022

iio: inkern: apply consumer scale when no channel scale is available



commit 14b457fdde38de594a4bc4bd9075019319d978da upstream.

When a consumer calls iio_read_channel_processed() and no channel scale
is available, it's assumed that the scale is one and the raw value is
returned as expected.

On the other hand, if the consumer calls iio_convert_raw_to_processed()
the scaling factor requested by the consumer is not applied.

This for example causes the consumer to process mV when expecting uV.
Make sure to always apply the scaling factor requested by the consumer.

Fixes: adc8ec5f ("iio: inkern: pass through raw values if no scaling")
Signed-off-by: Liam Beguin <liambeguin@gmail.com>
Reviewed-by: Peter Rosin <peda@axentia.se>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20220108205319.2046348-3-liambeguin@gmail.com


Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 5be8a07b

drivers/iio/inkern.c

+3 −3

Original line number	Original line	Diff line number	Diff line
	@@ -600,10 +600,10 @@ static int iio_convert_raw_to_processed_unlocked(struct iio_channel *chan,
	IIO_CHAN_INFO_SCALE);		IIO_CHAN_INFO_SCALE);
	if (scale_type < 0) {		if (scale_type < 0) {
	/*		/*
	* Just pass raw values as processed if no scaling is		* If no channel scaling is available apply consumer scale to
	* available.		* raw value and return.
	*/		*/
	*processed = raw;		processed = raw scale;
	return 0;		return 0;
	}		}