[PATCH 4.14 121/315] iio: accel: bma180: Fix buffer alignment in iio_push_to_buffers_with_timestamp()

[Greg Kroah-Hartman]

From: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>

[ Upstream commit fc36da3131a747a9367a05caf06de19be1bcc972 ]

To make code more readable, use a structure to express the channel
layout and ensure the timestamp is 8 byte aligned.

Found during an audit of all calls of this function.

Fixes: b9a6a237ffc9 ("iio:bma180: Drop _update_scan_mode()")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Cc: Peter Meerwald <pmeerw@xxxxxxxxxx>
Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
Link: https://lore.kernel.org/r/20210501170121.512209-2-jic23@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/iio/accel/bma180.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/accel/bma180.c b/drivers/iio/accel/bma180.c
index 3dec972ca672..dabe4717961f 100644
--- a/drivers/iio/accel/bma180.c
+++ b/drivers/iio/accel/bma180.c
@@ -121,7 +121,11 @@ struct bma180_data {
 	int scale;
 	int bw;
 	bool pmode;
-	u8 buff[16]; /* 3x 16-bit + 8-bit + padding + timestamp */
+	/* Ensure timestamp is naturally aligned */
+	struct {
+		s16 chan[4];
+		s64 timestamp __aligned(8);
+	} scan;
 };
 
 enum bma180_chan {
@@ -668,12 +672,12 @@ static irqreturn_t bma180_trigger_handler(int irq, void *p)
 			mutex_unlock(&data->mutex);
 			goto err;
 		}
-		((s16 *)data->buff)[i++] = ret;
+		data->scan.chan[i++] = ret;
 	}
 
 	mutex_unlock(&data->mutex);
 
-	iio_push_to_buffers_with_timestamp(indio_dev, data->buff, time_ns);
+	iio_push_to_buffers_with_timestamp(indio_dev, &data->scan, time_ns);
 err:
 	iio_trigger_notify_done(indio_dev->trig);
 
-- 
2.30.2