Re: [PATCH 04/19] iio: accel: kxcjk-1013: Fix buffer alignment in iio_push_to_buffers_with_timestamp()

[Andy Shevchenko <andy.shevchenko@gmail.com>]

On Sat, May 1, 2021 at 8:03 PM 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 this function.
>
> Fixes: 1a4fbf6a9286 ("iio: accel: kxcjk1013 3-axis accelerometer driver")
> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
> ---
>  drivers/iio/accel/kxcjk-1013.c | 24 ++++++++++++++----------
>  1 file changed, 14 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/iio/accel/kxcjk-1013.c b/drivers/iio/accel/kxcjk-1013.c
> index ff724bc17a45..96ab247f17b3 100644
> --- a/drivers/iio/accel/kxcjk-1013.c
> +++ b/drivers/iio/accel/kxcjk-1013.c
> @@ -133,6 +133,13 @@ enum kx_acpi_type {
>         ACPI_KIOX010A,
>  };
>
> +enum kxcjk1013_axis {
> +       AXIS_X,
> +       AXIS_Y,
> +       AXIS_Z,

> +       AXIS_MAX,

I see that this is from original code, though I think you have a
chance to remove unneeded comma here. Let's make the terminator line
terminate.

> +};
> +
>  struct kxcjk1013_data {
>         struct regulator_bulk_data regulators[2];
>         struct i2c_client *client;
> @@ -140,7 +147,11 @@ struct kxcjk1013_data {
>         struct iio_trigger *motion_trig;
>         struct iio_mount_matrix orientation;
>         struct mutex mutex;
> -       s16 buffer[8];
> +       /* Ensure timestamp naturally aligned */
> +       struct {
> +               s16 chans[AXIS_MAX];
> +               s64 timestamp __aligned(8);
> +       } scan;
>         u8 odr_bits;
>         u8 range;
>         int wake_thres;
> @@ -154,13 +165,6 @@ struct kxcjk1013_data {
>         enum kx_acpi_type acpi_type;
>  };
>
> -enum kxcjk1013_axis {
> -       AXIS_X,
> -       AXIS_Y,
> -       AXIS_Z,
> -       AXIS_MAX,
> -};
> -
>  enum kxcjk1013_mode {
>         STANDBY,
>         OPERATION,
> @@ -1094,12 +1098,12 @@ static irqreturn_t kxcjk1013_trigger_handler(int irq, void *p)
>         ret = i2c_smbus_read_i2c_block_data_or_emulated(data->client,
>                                                         KXCJK1013_REG_XOUT_L,
>                                                         AXIS_MAX * 2,
> -                                                       (u8 *)data->buffer);
> +                                                       (u8 *)data->scan.chans);
>         mutex_unlock(&data->mutex);
>         if (ret < 0)
>                 goto err;
>
> -       iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
> +       iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
>                                            data->timestamp);
>  err:
>         iio_trigger_notify_done(indio_dev->trig);
> --
> 2.31.1
>


-- 
With Best Regards,
Andy Shevchenko