Re: [PATCH v3 2/2] iio: pressure: bmp280: Use char instead of s32 for data buffer

[Kees Bakker]

Op 30-09-2024 om 22:23 schreef Vasileios Amoiridis:
> As it was reported and discussed here [1], storing the sensor data in an
> endian aware s32 buffer is not optimal. Advertising the timestamp as an
> addition of 2 s32 variables which is also implied is again not the best
> practice. For that reason, change the s32 sensor_data buffer to a u8
> buffer and align it properly.
>
> [1]: https://lore.kernel.org/linux-iio/73d13cc0-afb9-4306-b498-5d821728c3ba@stanley.mountain/
>
> Signed-off-by: Vasileios Amoiridis <vassilisamir@xxxxxxxxx>
> ---
>   drivers/iio/pressure/bmp280-core.c | 72 ++++++++++++++++++------------
>   drivers/iio/pressure/bmp280.h      |  4 +-
>   2 files changed, 46 insertions(+), 30 deletions(-)
> [...]
> @@ -2199,7 +2210,7 @@ static irqreturn_t bmp580_trigger_handler(int irq, void *p)
>   	struct iio_poll_func *pf = p;
>   	struct iio_dev *indio_dev = pf->indio_dev;
>   	struct bmp280_data *data = iio_priv(indio_dev);
> -	int ret;
> +	int ret, offset;
>   
>   	guard(mutex)(&data->lock);
>   
> @@ -2211,13 +2222,15 @@ static irqreturn_t bmp580_trigger_handler(int irq, void *p)
>   		goto out;
>   	}
>   
> -	/* Temperature calculations */
> -	memcpy(&data->sensor_data[1], &data->buf[0], 3);
> -
>   	/* Pressure calculations */
> -	memcpy(&data->sensor_data[0], &data->buf[3], 3);
> +	memcpy(&data->sensor_data[offset], &data->buf[3], 3);
Variable offset is not initialized.
> +
> +	offset += sizeof(s32);
> +
> +	/* Temperature calculations */
> +	memcpy(&data->sensor_data[offset], &data->buf[0], 3);
>   
> -	iio_push_to_buffers_with_timestamp(indio_dev, &data->sensor_data,
> +	iio_push_to_buffers_with_timestamp(indio_dev, data->sensor_data,
>   					   iio_get_time_ns(indio_dev));
>   
>   out: