On Sat, 1 May 2021 18:01:03 +0100
Jonathan Cameron <jic23@xxxxxxxxxx> wrote:
> From: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
>
> 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: b9a6a237ffc9 ("iio:bma180: Drop _update_scan_mode()")
> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> Cc: Peter Meerwald <pmeerw@xxxxxxxxxx>
Applied to the togreg branch of iio.git with a minor fix.
Note I'm taking these the slow way and nor marking them for stable
as they've been there a very long time.
> ---
> drivers/iio/accel/bma180.c | 10 +++++++---
> 1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/iio/accel/bma180.c b/drivers/iio/accel/bma180.c
> index b8a7469cdae4..2e901f900ea7 100644
> --- a/drivers/iio/accel/bma180.c
> +++ b/drivers/iio/accel/bma180.c
> @@ -162,7 +162,11 @@ struct bma180_data {
> int scale;
> int bw;
> bool pmode;
> - u8 buff[16]; /* 3x 16-bit + 8-bit + padding + timestamp */
> + /* Ensure timestamp is naturally aligned */
> + struct {
> + s16 chan[3];
The 8 bit in the comment above is misleading, but made me take another
look at this. There are actually 4 channels on some devices, the last
of which (temp) is 8 bits in a 16bit field.
I changed this to be s16 chan[4] to reflect that.
Thanks,
Jonathan
> + s64 timestamp __aligned(8);
> + } scan;
> };
>
> enum bma180_chan {
> @@ -938,12 +942,12 @@ static irqreturn_t bma180_trigger_handler(int irq, void *p)
> mutex_unlock(&data->mutex);
> goto err;
> }
> - ((s16 *)data->buff)[i++] = ret;
> + data->scan.chan[i++] = ret;
> }
>
> mutex_unlock(&data->mutex);
>
> - iio_push_to_buffers_with_timestamp(indio_dev, data->buff, time_ns);
> + iio_push_to_buffers_with_timestamp(indio_dev, &data->scan, time_ns);
> err:
> iio_trigger_notify_done(indio_dev->trig);
>
