[PATCH 4.19 179/421] iio: prox: pulsed-light: Fix buffer alignment in iio_push_to_buffers_with_timestamp()

Greg Kroah-Hartman
2021-07-19T16:17:52Z

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

[ Upstream commit 679cc377a03ff1944491eafc7355c1eb1fad4109 ]

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: cb119d535083 ("iio: proximity: add support for PulsedLight LIDAR")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Matt Ranostay <matt.ranostay@konsulko.com>
Acked-by: Matt Ranostay <matt.ranostay@konsulko.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20210501170121.512209-14-jic23@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/iio/proximity/pulsedlight-lidar-lite-v2.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/proximity/pulsedlight-lidar-lite-v2.c b/drivers/iio/proximity/pulsedlight-lidar-lite-v2.c
index 67f85268b63d..0c7617022407 100644
--- a/drivers/iio/proximity/pulsedlight-lidar-lite-v2.c
+++ b/drivers/iio/proximity/pulsedlight-lidar-lite-v2.c
@@ -43,7 +43,11 @@ struct lidar_data {
int (*xfer)(struct lidar_data *data, u8 reg, u8 *val, int len);
int i2c_enabled;

- u16 buffer[8]; /* 2 byte distance + 8 byte timestamp */
+ /* Ensure timestamp is naturally aligned */
+ struct {
+ u16 chan;
+ s64 timestamp __aligned(8);
+ } scan;
};

static const struct iio_chan_spec lidar_channels[] = {
@@ -228,9 +232,9 @@ static irqreturn_t lidar_trigger_handler(int irq, void *private)
struct lidar_data *data = iio_priv(indio_dev);
int ret;

- ret = lidar_get_measurement(data, data->buffer);
+ ret = lidar_get_measurement(data, &data->scan.chan);
if (!ret) {
- iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
+ iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
iio_get_time_ns(indio_dev));
} else if (ret != -EINVAL) {
dev_err(&data->client->dev, "cannot read LIDAR measurement");
--
2.30.2