Re: [PATCH v2 1/2] iio: accel: kionix-kx022a: use scan struct for one-shot and trigger reads

On 19/08/2026 00:51, Gabriel Rondon wrote:
> The driver kept two separate staging areas that hold the same thing:
> buffer[8], a DMA-aligned area used by the one-shot read in
> kx022a_get_axis() and by the triggered handler, and the scan struct,
> used by the FIFO flush path. Both are three __le16 channels plus room
> for the timestamp.
> 
> Drop buffer and route the one-shot read and the triggered handler
> through scan.channels, so the driver has a single staging area. Move the
> IIO_DMA_MINALIGN alignment onto scan, since it now backs the regmap bulk
> reads that buffer used to.
> 
> No functional change. get_axis() only runs via read_raw() under
> iio_device_claim_direct(), so it cannot run while the triggered buffer is
> active, and the triggered handler only runs while it is; the two never
> touch scan concurrently, exactly as they previously shared buffer.
> 
> Signed-off-by: Gabriel Rondon <[email protected]>

Suggested-by?

Other than that - looks good to me.

Reviewed-by: Matti Vaittinen <[email protected]>

> ---
>   drivers/iio/accel/kionix-kx022a.c | 15 +++++++--------
>   1 file changed, 7 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/iio/accel/kionix-kx022a.c b/drivers/iio/accel/kionix-kx022a.c
> index 02dd1db7a646..cf2cb751b4e8 100644
> --- a/drivers/iio/accel/kionix-kx022a.c
> +++ b/drivers/iio/accel/kionix-kx022a.c
> @@ -301,11 +301,10 @@ struct kx022a_data {
>   	__le16 *fifo_buffer;
>   
>   	/* 3 x 16bit accel data + timestamp */
> -	__le16 buffer[8] __aligned(IIO_DMA_MINALIGN);
>   	struct {
>   		__le16 channels[3];
>   		aligned_s64 ts;
> -	} scan;
> +	} scan __aligned(IIO_DMA_MINALIGN);
>   };
>   
>   static const struct iio_mount_matrix *
> @@ -613,12 +612,12 @@ static int kx022a_get_axis(struct kx022a_data *data,
>   {
>   	int ret;
>   
> -	ret = regmap_bulk_read(data->regmap, chan->address, &data->buffer[0],
> -			       sizeof(__le16));
> +	ret = regmap_bulk_read(data->regmap, chan->address,
> +			       &data->scan.channels[0], sizeof(__le16));
>   	if (ret)
>   		return ret;
>   
> -	*val = (s16)le16_to_cpu(data->buffer[0]);
> +	*val = (s16)le16_to_cpu(data->scan.channels[0]);
>   
>   	return IIO_VAL_INT;
>   }
> @@ -1029,12 +1028,12 @@ static irqreturn_t kx022a_trigger_handler(int irq, void *p)
>   	struct kx022a_data *data = iio_priv(idev);
>   	int ret;
>   
> -	ret = regmap_bulk_read(data->regmap, data->chip_info->xout_l, data->buffer,
> -			       KX022A_FIFO_SAMPLES_SIZE_BYTES);
> +	ret = regmap_bulk_read(data->regmap, data->chip_info->xout_l,
> +			       data->scan.channels, KX022A_FIFO_SAMPLES_SIZE_BYTES);
>   	if (ret < 0)
>   		goto err_read;
>   
> -	iio_push_to_buffers_with_timestamp(idev, data->buffer, data->timestamp);
> +	iio_push_to_buffers_with_timestamp(idev, &data->scan, data->timestamp);
>   err_read:
>   	iio_trigger_notify_done(idev->trig);
>   


-- 
Matti Vaittinen
Linux kernel developer at ROHM Semiconductors
Oulu Finland

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