This is a note to let you know that I've just added the patch titled iio: proximity: as3935: recalibrate RCO after resume to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: iio-proximity-as3935-recalibrate-rco-after-resume.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 6272c0de13abf1480f701d38288f28a11b4301c4 Mon Sep 17 00:00:00 2001 From: Matt Ranostay <matt.ranostay@xxxxxxxxxxxx> Date: Fri, 14 Apr 2017 16:38:19 -0700 Subject: iio: proximity: as3935: recalibrate RCO after resume 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 @@ -263,8 +263,6 @@ 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)); @@ -274,8 +272,6 @@ 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 @@ -312,6 +308,8 @@ 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); Patches currently in stable-queue which might be from matt.ranostay@xxxxxxxxxxxx are queue-4.4/iio-proximity-as3935-recalibrate-rco-after-resume.patch