| Message ID | 20210609193748.1709308-1-chris.lesiak@licor.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | iio: humidity: hdc100x: Add margin to the conversion time | expand |
On Wed, 9 Jun 2021 14:37:48 -0500 Chris Lesiak <chris.lesiak@licor.com> 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. > > Signed-off-by: Chris Lesiak <chris.lesiak@licor.com> Hi Chris Could you figure out a fixes tag for this one so we can get it backported into stable? If not I can probably guess when I catch up with applying patches. Thanks, Jonathan > --- > 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 */
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 */
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. Signed-off-by: Chris Lesiak <chris.lesiak@licor.com> --- drivers/iio/humidity/hdc100x.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)