[PATCH 4.4 079/188] iio: accel: stk8312: Fix buffer alignment in iio_push_to_buffers_with_timestamp()

Greg Kroah-Hartman
2021-07-19T15:01:44Z

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

[ Upstream commit f40a71ffec808e7e51848f63f0c0d3c32d65081b ]

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: 95c12bba51c3 ("iio: accel: Add buffer mode for Sensortek STK8312")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20210501170121.512209-7-jic23@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/iio/accel/stk8312.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/iio/accel/stk8312.c b/drivers/iio/accel/stk8312.c
index 85fe7f7247c1..945c80183f35 100644
--- a/drivers/iio/accel/stk8312.c
+++ b/drivers/iio/accel/stk8312.c
@@ -107,7 +107,11 @@ struct stk8312_data {
u8 mode;
struct iio_trigger *dready_trig;
bool dready_trigger_on;
- s8 buffer[16]; /* 3x8-bit channels + 5x8 padding + 64-bit timestamp */
+ /* Ensure timestamp is naturally aligned */
+ struct {
+ s8 chans[3];
+ s64 timestamp __aligned(8);
+ } scan;
};

static IIO_CONST_ATTR(in_accel_scale_available, STK8312_SCALE_AVAIL);
@@ -444,7 +448,7 @@ static irqreturn_t stk8312_trigger_handler(int irq, void *p)
ret = i2c_smbus_read_i2c_block_data(data->client,
STK8312_REG_XOUT,
STK8312_ALL_CHANNEL_SIZE,
- data->buffer);
+ data->scan.chans);
if (ret < STK8312_ALL_CHANNEL_SIZE) {
dev_err(&data->client->dev, "register read failed\n");
mutex_unlock(&data->lock);
@@ -458,12 +462,12 @@ static irqreturn_t stk8312_trigger_handler(int irq, void *p)
mutex_unlock(&data->lock);
goto err;
}
- data->buffer[i++] = ret;
+ data->scan.chans[i++] = ret;
}
}
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