From 196cc715dce3576a54065f5cb07185c75778f9a8 Mon Sep 17 00:00:00 2001 From: Matti Vaittinen Date: Mon, 10 Aug 2026 10:51:20 +0300 Subject: [PATCH] iio: adc: rohm-bd79124: Catch regmap errors at measurement start/stop The bd79124_start_measurement() and bd79124_stop_measurement() ignore errors from the regmap reads, causing potential use of uninitialized stack variable when deciding whether the measurement is already started/stopped. The bd79124_stop_measurement() may also ignore failure to clear the sequencer state bits, which may make the hardware to ignore the setting and leave hardware and driver states out of sync. Check the return value and bail-out if error is detected. Fixes: 3f57a3b9ab74 ("iio: adc: Support ROHM BD79124 ADC") Signed-off-by: Matti Vaittinen Cc: Signed-off-by: Jonathan Cameron --- drivers/iio/adc/rohm-bd79124.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/iio/adc/rohm-bd79124.c b/drivers/iio/adc/rohm-bd79124.c index f5b3096f553f..8091a138cca8 100644 --- a/drivers/iio/adc/rohm-bd79124.c +++ b/drivers/iio/adc/rohm-bd79124.c @@ -381,6 +381,9 @@ static int bd79124_start_measurement(struct bd79124_data *data, int chan) /* See if already started */ ret = regmap_read(data->map, BD79124_REG_AUTO_CHANNELS, &val); + if (ret) + return ret; + if (val & BIT(chan)) return 0; @@ -420,11 +423,16 @@ static int bd79124_stop_measurement(struct bd79124_data *data, int chan) /* See if already stopped */ ret = regmap_read(data->map, BD79124_REG_AUTO_CHANNELS, &enabled_chans); + if (ret) + return ret; + if (!(enabled_chans & BIT(chan))) return 0; ret = regmap_clear_bits(data->map, BD79124_REG_SEQ_CFG, BD79124_MSK_SEQ_START); + if (ret) + return ret; /* Clear the channel from the measured channels */ enabled_chans &= ~BIT(chan);