patch "IIO: BME280: Updates to Humidity readings need ctrl_reg write!" added to staging-linus

patch "IIO: BME280: Updates to Humidity readings need ctrl_reg write!" added to staging-linus

[gregkh]

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 my staging git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git
in the staging-linus branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.

If you have any questions about this process, please let me know.


>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!

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>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
 drivers/iio/pressure/bmp280-core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
index d82b788374b6..e442c5248427 100644
--- a/drivers/iio/pressure/bmp280-core.c
+++ b/drivers/iio/pressure/bmp280-core.c
@@ -558,7 +558,7 @@ static int bmp280_chip_config(struct bmp280_data *data)
 	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,
-- 
2.14.1