[PATCH 4.19 177/421] iio: humidity: am2315: Fix buffer alignment in iio_push_to_buffers_with_timestamp()

Greg Kroah-Hartman
2021-07-19T16:17:43Z

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

[ Upstream commit f4ca2e2595d9fee65d5ce0d218b22ce00e5b2915 ]

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: 0d96d5ead3f7 ("iio: humidity: Add triggered buffer support for AM2315")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20210501170121.512209-12-jic23@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/iio/humidity/am2315.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/iio/humidity/am2315.c b/drivers/iio/humidity/am2315.c
index 7d8669dc6547..b09bd0b39c9c 100644
--- a/drivers/iio/humidity/am2315.c
+++ b/drivers/iio/humidity/am2315.c
@@ -36,7 +36,11 @@
struct am2315_data {
struct i2c_client *client;
struct mutex lock;
- s16 buffer[8]; /* 2x16-bit channels + 2x16 padding + 4x16 timestamp */
+ /* Ensure timestamp is naturally aligned */
+ struct {
+ s16 chans[2];
+ s64 timestamp __aligned(8);
+ } scan;
};

struct am2315_sensor_data {
@@ -170,20 +174,20 @@ static irqreturn_t am2315_trigger_handler(int irq, void *p)

mutex_lock(&data->lock);
if (*(indio_dev->active_scan_mask) == AM2315_ALL_CHANNEL_MASK) {
- data->buffer[0] = sensor_data.hum_data;
- data->buffer[1] = sensor_data.temp_data;
+ data->scan.chans[0] = sensor_data.hum_data;
+ data->scan.chans[1] = sensor_data.temp_data;
} else {
i = 0;
for_each_set_bit(bit, indio_dev->active_scan_mask,
indio_dev->masklength) {
- data->buffer[i] = (bit ? sensor_data.temp_data :
- sensor_data.hum_data);
+ data->scan.chans[i] = (bit ? sensor_data.temp_data :
+ sensor_data.hum_data);
i++;
}
}
mutex_unlock(&data->lock);

- iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
+ iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
pf->timestamp);
err:
iio_trigger_notify_done(indio_dev->trig);
--
2.30.2