Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 5.4 02/62] iio: humidity: hdc100x: Add margin to the conversion time | Date | Mon, 16 Aug 2021 15:01:34 +0200 |
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From: Chris Lesiak <chris.lesiak@licor.com>
commit 84edec86f449adea9ee0b4912a79ab8d9d65abb7 upstream.
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@licor.com> Acked-by: Matt Ranostay <matt.ranostay@konsulko.com> Link: https://lore.kernel.org/r/20210614141820.2034827-1-chris.lesiak@licor.com Cc: <Stable@vger.kernel.org> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/iio/humidity/hdc100x.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
--- a/drivers/iio/humidity/hdc100x.c +++ b/drivers/iio/humidity/hdc100x.c @@ -24,6 +24,8 @@ #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 @@ -165,7 +167,7 @@ static int hdc100x_get_measurement(struc 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; @@ -322,7 +324,7 @@ static irqreturn_t hdc100x_trigger_handl 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 */
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