4.11-stable review patch. If anyone has any objections, please let me know. ------------------ From: Matt Ranostay <matt.ranostay@xxxxxxxxxxxx> commit 6272c0de13abf1480f701d38288f28a11b4301c4 upstream. According to the datasheet the RCO must be recalibrated on every power-on-reset. Also remove mutex locking in the calibration function since callers other than the probe function (which doesn't need it) will have a lock. Fixes: 24ddb0e4bba4 ("iio: Add AS3935 lightning sensor support") Cc: George McCollister <george.mccollister@xxxxxxxxx> Signed-off-by: Matt Ranostay <matt.ranostay@xxxxxxxxxxxx> Signed-off-by: Jonathan Cameron <jic23@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/iio/proximity/as3935.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) --- a/drivers/iio/proximity/as3935.c +++ b/drivers/iio/proximity/as3935.c @@ -269,8 +269,6 @@ static irqreturn_t as3935_interrupt_hand static void calibrate_as3935(struct as3935_state *st) { - mutex_lock(&st->lock); - /* mask disturber interrupt bit */ as3935_write(st, AS3935_INT, BIT(5)); @@ -280,8 +278,6 @@ static void calibrate_as3935(struct as39 mdelay(2); as3935_write(st, AS3935_TUNE_CAP, (st->tune_cap / TUNE_CAP_DIV)); - - mutex_unlock(&st->lock); } #ifdef CONFIG_PM_SLEEP @@ -318,6 +314,8 @@ static int as3935_resume(struct device * val &= ~AS3935_AFE_PWR_BIT; ret = as3935_write(st, AS3935_AFE_GAIN, val); + calibrate_as3935(st); + err_resume: mutex_unlock(&st->lock);