[PATCH v2] iio: humidity: hdc100x: Add margin to the conversion time

From: Chris Lesiak
Date: Thu Jun 10 2021 - 09:45:26 EST


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 | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/humidity/hdc100x.c b/drivers/iio/humidity/hdc100x.c
index 2a957f19048e..91790aa8beeb 100644
--- a/drivers/iio/humidity/hdc100x.c
+++ b/drivers/iio/humidity/hdc100x.c
@@ -166,7 +166,7 @@ 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] + 1000;
int ret;
__be16 val;

@@ -316,7 +316,7 @@ 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] + 2000;
int ret;

/* dual read starts at temp register */
--
2.26.2