On Mon, 14 Jun 2021 09:18:20 -0500
Chris Lesiak <chris.lesiak@xxxxxxxxx> wrote:
> 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>
+CC Matt as this is one of his drivers.
Looks good to me.
> ---
> 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 */
