The trigger path used a plain s16 buffer while the FIFO path already had
a properly typed scan member (__le16 + aligned timestamp). Those two
buffers did the same job, and s16 does not represent little-endian data.
Drop the duplicate, keep scan at the end of struct bmc150_accel_data with
IIO_DMA_MINALIGN, and use it for both the trigger and FIFO paths.

The FIFO and read_raw buffers are passed to regmap bulk/raw reads, which
is not DMA-safe. Move them into struct bmc150_accel_data after the aligned
scan buffer. Because all buffers are serialized by data->mutex, placing
them after scan ensures DMA safety without needing separate alignment.

Finally, replace the deprecated iio_push_to_buffers_with_timestamp() with
iio_push_to_buffers_with_ts() so the push sites pass an explicit buffer
size.

This supersedes the earlier standalone patches:
Link: https://lore.kernel.org/linux-iio/20260808220236.421832-1-yashsuthar983@gmail.com/
Link: https://lore.kernel.org/linux-iio/20260809111303.496393-1-yashsuthar983@gmail.com/

Link to v1: https://lore.kernel.org/all/20260814101845.301769-1-yashsuthar983@gmail.com/
Link to v2: https://lore.kernel.org/linux-iio/20260815175728.99541-1-yashsuthar983@gmail.com/

Changes in v3:
- patch 1: hold mutex for both the read and push to guarantee DMA safety
- patch 1: drop unused AXIS_MAX and use sizeof(data->scan.channels)
- patch 2: remove redundant __aligned(IIO_DMA_MINALIGN) from fifo_buff 
  and regval, as the mutex serializes access
- patch 2: fix comma typo in commit message

Changes in v2:
- patch 1: restore early error check flow
- patch 2: keep fifo_buff declaration in one line

Yash Suthar (3):
  iio: accel: bmc150: use aligned scan buffer for both trigger and fifo
  iio: accel: bmc150: use DMA-safe buffers for regmap bulk reads
  iio: accel: bmc150: use iio_push_to_buffers_with_ts()

 drivers/iio/accel/bmc150-accel-core.c | 28 +++++++++++++--------------
 drivers/iio/accel/bmc150-accel.h      | 19 +++++++++---------
 2 files changed, 23 insertions(+), 24 deletions(-)

-- 
2.43.0

On Tue, Aug 25, 2026 at 02:21:53PM +0530, Yash Suthar wrote:
> The trigger path used a plain s16 buffer while the FIFO path already had
> a properly typed scan member (__le16 + aligned timestamp). Those two
> buffers did the same job, and s16 does not represent little-endian data.
> Drop the duplicate, keep scan at the end of struct bmc150_accel_data with
> IIO_DMA_MINALIGN, and use it for both the trigger and FIFO paths.
> 
> The FIFO and read_raw buffers are passed to regmap bulk/raw reads, which
> is not DMA-safe. Move them into struct bmc150_accel_data after the aligned
> scan buffer. Because all buffers are serialized by data->mutex, placing
> them after scan ensures DMA safety without needing separate alignment.
> 
> Finally, replace the deprecated iio_push_to_buffers_with_timestamp() with
> iio_push_to_buffers_with_ts() so the push sites pass an explicit buffer
> size.
> 
> This supersedes the earlier standalone patches:
> Link: https://lore.kernel.org/linux-iio/20260808220236.421832-1-yashsuthar983@gmail.com/
> Link: https://lore.kernel.org/linux-iio/20260809111303.496393-1-yashsuthar983@gmail.com/

In this case it's better not to use Link: tag. `b4` can't distinguish them from
the important ones.

> Link to v1: https://lore.kernel.org/all/20260814101845.301769-1-yashsuthar983@gmail.com/
> Link to v2: https://lore.kernel.org/linux-iio/20260815175728.99541-1-yashsuthar983@gmail.com/

-- 
With Best Regards,
Andy Shevchenko