On Mon, 18 Sep 2017 12:05:30 +0200 Fabrice Gasnier <fabrice.gasn...@st.com> wrote:
> Currently, setting preset value (ARR) will update directly 'Auto reload > value' only on 1st write access. But then, ARPE is set. This makes > ARR a shadow register. Preset value should be updated upon each > write request: ensure ARPE is 0. This fixes successive writes to > preset attribute. > > Fixes: 4adec7da0536 ("iio: stm32 trigger: Add quadrature encoder device") > > Signed-off-by: Fabrice Gasnier <fabrice.gasn...@st.com> Applied to the fixes-togreg-post-rc1 branch of iio.git and marked for stable. Thanks, Jonathan > --- > drivers/iio/trigger/stm32-timer-trigger.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/iio/trigger/stm32-timer-trigger.c > b/drivers/iio/trigger/stm32-timer-trigger.c > index 9b90534..34cc25b 100644 > --- a/drivers/iio/trigger/stm32-timer-trigger.c > +++ b/drivers/iio/trigger/stm32-timer-trigger.c > @@ -715,8 +715,9 @@ static ssize_t stm32_count_set_preset(struct iio_dev > *indio_dev, > if (ret) > return ret; > > + /* TIMx_ARR register shouldn't be buffered (ARPE=0) */ > + regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_ARPE, 0); > regmap_write(priv->regmap, TIM_ARR, preset); > - regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_ARPE, TIM_CR1_ARPE); > > return len; > }