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 4.13-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-4.13 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 4b1f0c31f96c45e8521dd84aae50f2aa4aecfb7b Mon Sep 17 00:00:00 2001 From: Colin Parker <colin.parker@xxxxxxxxx> 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@xxxxxxxxx> 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@xxxxxxxxx> Acked-by: Andreas Klinger <ak@xxxxxxxxxxxxx> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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 @@ -573,7 +573,7 @@ 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@xxxxxxxxx are queue-4.13/iio-bme280-updates-to-humidity-readings-need-ctrl_reg-write.patch