Patch "IIO: BME280: Updates to Humidity readings need ctrl_reg write!" has been added to the 4.9-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    IIO: BME280: Updates to Humidity readings need ctrl_reg write!

to the 4.9-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-bme280-updates-to-humidity-readings-need-ctrl_reg-write.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 4b1f0c31f96c45e8521dd84aae50f2aa4aecfb7b Mon Sep 17 00:00:00 2001
From: Colin Parker <colin.parker@aclima.io>
Date: Mon, 28 Aug 2017 16:21:39 -0700
Subject: IIO: BME280: Updates to Humidity readings need ctrl_reg write!

From: Colin Parker <colin.parker@aclima.io>

commit 4b1f0c31f96c45e8521dd84aae50f2aa4aecfb7b upstream.

The ctrl_reg register needs to be written after any write to
the humidity registers. The value written to the ctrl_reg register
does not necessarily need to change, but a write operation must
occur.

The regmap_update_bits functions will not write to a register
if the register value matches the value to be written. This saves
unnecessary bus operations.  The change in this patch forces a bus
write during the chip_config operation by switching to
regmap_write_bits.

This will fix issues where the Humidity Sensor Oversampling bits
are not updated after initialization.

Signed-off-by: Colin Parker <colin.parker@aclima.io>
Acked-by: Andreas Klinger <ak@it-klinger.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/iio/pressure/bmp280-core.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/iio/pressure/bmp280-core.c
+++ b/drivers/iio/pressure/bmp280-core.c
@@ -558,7 +558,7 @@ static int bmp280_chip_config(struct bmp
 	u8 osrs = BMP280_OSRS_TEMP_X(data->oversampling_temp + 1) |
 		  BMP280_OSRS_PRESS_X(data->oversampling_press + 1);
 
-	ret = regmap_update_bits(data->regmap, BMP280_REG_CTRL_MEAS,
+	ret = regmap_write_bits(data->regmap, BMP280_REG_CTRL_MEAS,
 				 BMP280_OSRS_TEMP_MASK |
 				 BMP280_OSRS_PRESS_MASK |
 				 BMP280_MODE_MASK,


Patches currently in stable-queue which might be from colin.parker@aclima.io are

queue-4.9/iio-bme280-updates-to-humidity-readings-need-ctrl_reg-write.patch