[PATCH 5.4 276/348] iio: magn: bmc150: Fix buffer alignment in iio_push_to_buffers_with_timestamp()

From: Greg Kroah-Hartman
Date: Mon Jul 12 2021 - 02:38:10 EST


From: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>

[ Upstream commit 7692088f72865c41b6b531fd09486ee99a5da930 ]

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 uses of
iio_push_to_buffers_with_timestamp()

Fixes: c91746a2361d ("iio: magn: Add support for BMC150 magnetometer")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Cc: Stephan Gerhold <stephan@xxxxxxxxxxx>
Cc: Linus Walleij <linus.walleij@xxxxxxxxxx>
Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
Link: https://lore.kernel.org/r/20210501170121.512209-17-jic23@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/iio/magnetometer/bmc150_magn.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/iio/magnetometer/bmc150_magn.c b/drivers/iio/magnetometer/bmc150_magn.c
index d4de16750b10..48685d785c1b 100644
--- a/drivers/iio/magnetometer/bmc150_magn.c
+++ b/drivers/iio/magnetometer/bmc150_magn.c
@@ -136,8 +136,11 @@ struct bmc150_magn_data {
struct mutex mutex;
struct regmap *regmap;
struct iio_mount_matrix orientation;
- /* 4 x 32 bits for x, y z, 4 bytes align, 64 bits timestamp */
- s32 buffer[6];
+ /* Ensure timestamp is naturally aligned */
+ struct {
+ s32 chans[3];
+ s64 timestamp __aligned(8);
+ } scan;
struct iio_trigger *dready_trig;
bool dready_trigger_on;
int max_odr;
@@ -673,11 +676,11 @@ static irqreturn_t bmc150_magn_trigger_handler(int irq, void *p)
int ret;

mutex_lock(&data->mutex);
- ret = bmc150_magn_read_xyz(data, data->buffer);
+ ret = bmc150_magn_read_xyz(data, data->scan.chans);
if (ret < 0)
goto err;

- iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
+ iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
pf->timestamp);

err:
--
2.30.2