[PATCH 4.4 078/188] iio: accel: bma180: Fix buffer alignment in iio_push_to_buffers_with_timestamp()

Greg Kroah-Hartman
2021-07-19T15:01:43Z

From: Jonathan Cameron <Jonathan.Cameron@huawei.com>

[ 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@huawei.com>
Cc: Peter Meerwald <pmeerw@pmeerw.net>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20210501170121.512209-2-jic23@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 f04b88406995..68c9e5478fec 100644
--- a/drivers/iio/accel/bma180.c
+++ b/drivers/iio/accel/bma180.c
@@ -120,7 +120,11 @@ 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 {
@@ -666,12 +670,12 @@ 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