This is a note to let you know that I've just added the patch titled
iio: trigger: stm32-timer: preset shouldn't be buffered
to my staging git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git
in the staging-linus branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.
If you have any questions about this process, please let me know.
>From 0a56eabc4e3f730782e4a9f3af4f60aa03a8a849 Mon Sep 17 00:00:00 2001
From: Fabrice Gasnier <fabrice.gasnier@xxxxxx>
Date: Mon, 18 Sep 2017 12:05:30 +0200
Subject: iio: trigger: stm32-timer: preset shouldn't be buffered
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.gasnier@xxxxxx>
Cc: <Stable@xxxxxxxxxxxxxxx>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
---
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 a9bc5b603b86..4cec28af3ecf 100644
--- a/drivers/iio/trigger/stm32-timer-trigger.c
+++ b/drivers/iio/trigger/stm32-timer-trigger.c
@@ -681,8 +681,9 @@ 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;
}
--
2.14.1