[PATCH 4.4 26/70] iio: xilinx-xadc: Fix ADC-B powerdown
From: Greg Kroah-Hartman
Date:  Fri May 01 2020 - 09:26:28 EST
From: Lars-Peter Clausen <lars@xxxxxxxxxx>
commit e44ec7794d88f918805d700240211a9ec05ed89d upstream.
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@xxxxxxxxxx>
Fixes: bdc8cda1d010 ("iio:adc: Add Xilinx XADC driver")
Cc: <Stable@xxxxxxxxxxxxxxx>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/iio/adc/xilinx-xadc-core.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
--- a/drivers/iio/adc/xilinx-xadc-core.c
+++ b/drivers/iio/adc/xilinx-xadc-core.c
@@ -709,13 +709,14 @@ static int xadc_power_adc_b(struct xadc
 {
 	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;
 	}