[PATCH 4.13 088/160] iio: trigger: stm32-timer: fix a corner case to write preset

[Greg Kroah-Hartman]

4.13-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Fabrice Gasnier <fabrice.gasnier@xxxxxx>

commit b7a9776c1f9443326632486fcbd82dca82f8511e upstream.

Balance timer start routine that sets ARPE: clear it in stop routine.
This fixes a corner case, when timer is used successively as trigger
(with sampling_frequency start/stop routines), then as a counter
(with preset).

Fixes: 93fbe91b5521 ("iio: Add STM32 timer trigger driver")
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@xxxxxx>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/iio/trigger/stm32-timer-trigger.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/iio/trigger/stm32-timer-trigger.c
+++ b/drivers/iio/trigger/stm32-timer-trigger.c
@@ -138,6 +138,7 @@ static void stm32_timer_stop(struct stm3
 		clk_disable(priv->clk);
 
 	/* Stop timer */
+	regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_ARPE, 0);
 	regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, 0);
 	regmap_write(priv->regmap, TIM_PSC, 0);
 	regmap_write(priv->regmap, TIM_ARR, 0);