The datasheets have the following note for the conversion time specification: "This parameter is specified by design and/or characterization and it is not tested in production." Parts have been seen that require more time to do 14-bit conversions for the relative humidity channel. The result is ENXIO due to the address phase of a transfer not getting an ACK. Delay an additional 1 ms per conversion to allow for additional margin. Fixes: 4839367d99e3 ("iio: humidity: add HDC100x support") Signed-off-by: Chris Lesiak <chris.lesiak@xxxxxxxxx> --- drivers/iio/humidity/hdc100x.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/iio/humidity/hdc100x.c b/drivers/iio/humidity/hdc100x.c index 2a957f19048e..9e0fce917ce4 100644 --- a/drivers/iio/humidity/hdc100x.c +++ b/drivers/iio/humidity/hdc100x.c @@ -25,6 +25,8 @@ #include <linux/iio/trigger_consumer.h> #include <linux/iio/triggered_buffer.h> +#include <linux/time.h> + #define HDC100X_REG_TEMP 0x00 #define HDC100X_REG_HUMIDITY 0x01 @@ -166,7 +168,7 @@ static int hdc100x_get_measurement(struct hdc100x_data *data, struct iio_chan_spec const *chan) { struct i2c_client *client = data->client; - int delay = data->adc_int_us[chan->address]; + int delay = data->adc_int_us[chan->address] + 1*USEC_PER_MSEC; int ret; __be16 val; @@ -316,7 +318,7 @@ static irqreturn_t hdc100x_trigger_handler(int irq, void *p) struct iio_dev *indio_dev = pf->indio_dev; struct hdc100x_data *data = iio_priv(indio_dev); struct i2c_client *client = data->client; - int delay = data->adc_int_us[0] + data->adc_int_us[1]; + int delay = data->adc_int_us[0] + data->adc_int_us[1] + 2*USEC_PER_MSEC; int ret; /* dual read starts at temp register */ -- 2.26.2