patch "iio: common: st_sensors: fix channel data parsing" added to staging-linus

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

iio: common: st_sensors: fix channel data parsing

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: Lorenzo Bianconi <[email protected]>
Date: Wed, 16 Nov 2016 22:15:28 +0100
Subject: iio: common: st_sensors: fix channel data parsing

Using realbits as i2c/spi read len, when that value is not byte aligned (e.g 12 bits), lead to skip msb part of out data registers. Fix this taking into account scan_type.shift in addition to scan_type.realbits as read length:

read_len = DIV_ROUND_UP(realbits + shift, 8)

This fix has been tested on 8, 12, 16, 24 bit sensors

---
 drivers/iio/common/st_sensors/st_sensors_buffer.c | 4 +++-
 drivers/iio/common/st_sensors/st_sensors_core.c   | 4 +++-
 2 files changed, 6 insertions(+), 2 deletions(-)

index fe7775bb3740..df4045203a07 100644
@@ -30,7 +30,9 @@ static int st_sensors_get_buffer_element(struct iio_dev *indio_dev, u8 *buf)
 
 	for_each_set_bit(i, indio_dev->active_scan_mask, num_data_channels) {
 		const struct iio_chan_spec *channel = &indio_dev->channels[i];
-		unsigned int bytes_to_read = channel->scan_type.realbits >> 3;
+		unsigned int bytes_to_read =
+			DIV_ROUND_UP(channel->scan_type.realbits +
+				     channel->scan_type.shift, 8);
 		unsigned int storage_bytes =
 			channel->scan_type.storagebits >> 3;
 

index 975a1f19f747..d5cf7f31eaf9 100644
@@ -483,8 +483,10 @@ static int st_sensors_read_axis_data(struct iio_dev *indio_dev,
 	int err;
 	u8 *outdata;
 	struct st_sensor_data *sdata = iio_priv(indio_dev);
-	unsigned int byte_for_channel = ch->scan_type.realbits >> 3;
+	unsigned int byte_for_channel;
 
+	byte_for_channel = DIV_ROUND_UP(ch->scan_type.realbits +
+					ch->scan_type.shift, 8);
 	outdata = kmalloc(byte_for_channel, GFP_KERNEL);
 	if (!outdata)
 		return -ENOMEM;

2.11.0