Re: [PATCH 1/5] iio: xilinx-xadc: Fix ADC-B powerdown

[Jonathan Cameron <jic23@kernel.org>]

On Fri,  3 Apr 2020 15:27:13 +0200
Lars-Peter Clausen <lars@metafoo.de> wrote:

> The check for shutting down the second ADC is inverted. This causes it to
> be powered down when it should be enabled. As a result channels that are
> supposed to be handled by the second ADC return invalid conversion results.
> 
> Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>

Fixes tag?  Definitely sounds like something we should be backporting!

Jonathan

> ---
>  drivers/iio/adc/xilinx-xadc-core.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/iio/adc/xilinx-xadc-core.c b/drivers/iio/adc/xilinx-xadc-core.c
> index 2d6505a66511..4fcf1729341f 100644
> --- a/drivers/iio/adc/xilinx-xadc-core.c
> +++ b/drivers/iio/adc/xilinx-xadc-core.c
> @@ -722,13 +722,14 @@ static int xadc_power_adc_b(struct xadc *xadc, unsigned int seq_mode)
>  {
>  	uint16_t val;
>  
> +	/* Powerdown the ADC-B when it is not needed. */
>  	switch (seq_mode) {
>  	case XADC_CONF1_SEQ_SIMULTANEOUS:
>  	case XADC_CONF1_SEQ_INDEPENDENT:
> -		val = XADC_CONF2_PD_ADC_B;
> +		val = 0;
>  		break;
>  	default:
> -		val = 0;
> +		val = XADC_CONF2_PD_ADC_B;
>  		break;
>  	}
>