[PATCH 4.19 173/421] iio: accel: stk8ba50: 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 334883894bc1e145a1e0f5de1b0d1b6a1133f0e6 ]

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: db6a19b8251f ("iio: accel: Add trigger support for STK8BA50")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20210501170121.512209-8-jic23@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/iio/accel/stk8ba50.c | 17 ++++++++---------
1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/drivers/iio/accel/stk8ba50.c b/drivers/iio/accel/stk8ba50.c
index 576b6b140f08..0d9067d3ccc4 100644
--- a/drivers/iio/accel/stk8ba50.c
+++ b/drivers/iio/accel/stk8ba50.c
@@ -94,12 +94,11 @@ struct stk8ba50_data {
u8 sample_rate_idx;
struct iio_trigger *dready_trig;
bool dready_trigger_on;
- /*
- * 3 x 16-bit channels (10-bit data, 6-bit padding) +
- * 1 x 16 padding +
- * 4 x 16 64-bit timestamp
- */
- s16 buffer[8];
+ /* Ensure timestamp is naturally aligned */
+ struct {
+ s16 chans[3];
+ s64 timetamp __aligned(8);
+ } scan;
};

#define STK8BA50_ACCEL_CHANNEL(index, reg, axis) { \
@@ -327,7 +326,7 @@ static irqreturn_t stk8ba50_trigger_handler(int irq, void *p)
ret = i2c_smbus_read_i2c_block_data(data->client,
STK8BA50_REG_XOUT,
STK8BA50_ALL_CHANNEL_SIZE,
- (u8 *)data->buffer);
+ (u8 *)data->scan.chans);
if (ret < STK8BA50_ALL_CHANNEL_SIZE) {
dev_err(&data->client->dev, "register read failed\n");
goto err;
@@ -340,10 +339,10 @@ static irqreturn_t stk8ba50_trigger_handler(int irq, void *p)
if (ret < 0)
goto err;

- data->buffer[i++] = ret;
+ data->scan.chans[i++] = ret;
}
}
- iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
+ iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
pf->timestamp);
err:
mutex_unlock(&data->lock);
--
2.30.2