Re: [PATCH 13/19] iio: prox: pulsed-light: Fix buffer alignment in iio_push_to_buffers_with_timestamp()

[Matt Ranostay <matt.ranostay@konsulko.com>]

On Sat, May 1, 2021 at 10:03 AM Jonathan Cameron <jic23@kernel.org> wrote:
>
> From: Jonathan Cameron <Jonathan.Cameron@huawei.com>
>
> 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>

Acked-by: Matt Ranostay <matt.ranostay@konsulko.com>

> Cc: Matt Ranostay <matt.ranostay@konsulko.com>
> ---
>  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 c685f10b5ae4..822a68ae5e03 100644
> --- a/drivers/iio/proximity/pulsedlight-lidar-lite-v2.c
> +++ b/drivers/iio/proximity/pulsedlight-lidar-lite-v2.c
> @@ -44,7 +44,11 @@ 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[] = {
> @@ -229,9 +233,9 @@ 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");
> --
> 2.31.1
>