On Wed, 6 Dec 2017 09:52:20 +0100
Andreas Klinger <a...@it-klinger.de> wrote:
> Return value in hx711_reset() should indicate status of dout otherwise the
> calling function is reporting an error as false positive
>
> If there are two reads too close to each other, then the second one will
> never succeed. This happens especially when using buffered mode with both
> channels enabled.
>
> When changing the channel on every trigger event the former 100 ms are not
> enough for waiting until the device indicates normal mode.
>
> Wait up to 1 second until the device turns into normal mode.
>
> Signed-off-by: Andreas Klinger <a...@it-klinger.de>
This looks fine to me. I'll pick it up once patch 1 is ready.
Thanks,
Jonathan
> ---
> drivers/iio/adc/hx711.c | 13 ++++++-------
> 1 file changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/iio/adc/hx711.c b/drivers/iio/adc/hx711.c
> index 37982b93a227..0a2d0b6cd38a 100644
> --- a/drivers/iio/adc/hx711.c
> +++ b/drivers/iio/adc/hx711.c
> @@ -153,15 +153,16 @@ static int hx711_wait_for_ready(struct hx711_data
> *hx711_data)
> int i, val;
>
> /*
> - * a maximum reset cycle time of 56 ms was measured.
> - * we round it up to 100 ms
> + * in some rare cases the reset takes quite a long time
> + * especially when the channel is changed.
> + * Allow up to one second for it
> */
> for (i = 0; i < 100; i++) {
> val = gpiod_get_value(hx711_data->gpiod_dout);
> if (!val)
> break;
> - /* sleep at least 1 ms */
> - msleep(1);
> + /* sleep at least 10 ms */
> + msleep(10);
> }
> if (val)
> return -EIO;
> @@ -203,9 +204,7 @@ static int hx711_reset(struct hx711_data *hx711_data)
> * after a dummy read we need to wait vor readiness
> * for not mixing gain pulses with the clock
> */
> - ret = hx711_wait_for_ready(hx711_data);
> - if (ret)
> - return ret;
> + val = hx711_wait_for_ready(hx711_data);
> }
>
> return val;
