Re: [PATCH 1/1] iio: imu: adis16475.c: Add buffer padding after temp channel

[Nuno Sá]

On Tue, 2023-09-26 at 11:57 +0300, Ramona Gradinariu wrote:
> The temperature channel has 16-bit storage size. We need to perform
> the padding to have the buffer elements naturally aligned in case
> the temperature channel is enabled and there are any 32-bit storage
> size channels enabled which have a scan index higher than the
> temperature channel scan index.
> 
> Fixes: 8f6bc87d67c0 ("iio: imu: adis16475.c: Add delta angle and delta
> velocity channels")
> Signed-off-by: Ramona Gradinariu <ramona.gradinariu@xxxxxxxxxx>
> ---

Reviewed-by: Nuno Sa <nuno.sa@xxxxxxxxxx>

>  drivers/iio/imu/adis16475.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/drivers/iio/imu/adis16475.c b/drivers/iio/imu/adis16475.c
> index 00e4e09cdafb..9af07fec0d89 100644
> --- a/drivers/iio/imu/adis16475.c
> +++ b/drivers/iio/imu/adis16475.c
> @@ -1197,6 +1197,16 @@ static irqreturn_t adis16475_trigger_handler(int irq,
> void *p)
>                 switch (bit) {
>                 case ADIS16475_SCAN_TEMP:
>                         st->data[i++] = buffer[offset];
> +                       /*
> +                        * The temperature channel has 16-bit storage size.
> +                        * We need to perform the padding to have the buffer
> +                        * elements naturally aligned in case there are any
> +                        * 32-bit storage size channels enabled which have a
> +                        * scan index higher than the temperature channel scan
> +                        * index.
> +                        */
> +                       if (*indio_dev->active_scan_mask &
> GENMASK(ADIS16475_SCAN_DELTVEL_Z, ADIS16475_SCAN_DELTANG_X))
> +                               st->data[i++] = 0;

You could use ADIS16500_BURST_DATA_SEL_1_CHN_MASK but I kind of agree like this
is more obvious what's going on...

>                         break;
>                 case ADIS16475_SCAN_DELTANG_X ... ADIS16475_SCAN_DELTVEL_Z:
>                         buff_offset = ADIS16475_SCAN_DELTANG_X;