[PATCH v6 1/3] iio: imu: inv_icm42600: reorganize DMA aligned buffers in structure

Jean-Baptiste Maneyrol via B4 Relay posted 3 patches 3 months, 1 week ago
[PATCH v6 1/3] iio: imu: inv_icm42600: reorganize DMA aligned buffers in structure
Posted by Jean-Baptiste Maneyrol via B4 Relay 3 months, 1 week ago
From: Jean-Baptiste Maneyrol <jean-baptiste.maneyrol@tdk.com>

Move all DMA aligned buffers together at the end of the structure.

1. Timestamp anynomous structure is not used with DMA so it doesn't
belong after __aligned(IIO_DMA_MINALIGN).
2. struct inv_icm42600_fifo contains it's own __aligned(IIO_DMA_MINALIGN)
within it at the end so it should not be after __aligned(IIO_DMA_MINALIGN)
in the outer struct either.
3. Normally 1 would have been considered a bug, but because of the extra
alignment from 2, it actually was OK, but we shouldn't be relying on such
quirks.

Signed-off-by: Jean-Baptiste Maneyrol <jean-baptiste.maneyrol@tdk.com>
---
 drivers/iio/imu/inv_icm42600/inv_icm42600.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/iio/imu/inv_icm42600/inv_icm42600.h b/drivers/iio/imu/inv_icm42600/inv_icm42600.h
index 55ed1ddaa8cb5dd410d17db3866fa0f22f18e9d2..9b2cce172670c5513f18d5979a5ff563e9af4cb3 100644
--- a/drivers/iio/imu/inv_icm42600/inv_icm42600.h
+++ b/drivers/iio/imu/inv_icm42600/inv_icm42600.h
@@ -148,9 +148,9 @@ struct inv_icm42600_suspended {
  *  @suspended:		suspended sensors configuration.
  *  @indio_gyro:	gyroscope IIO device.
  *  @indio_accel:	accelerometer IIO device.
- *  @buffer:		data transfer buffer aligned for DMA.
- *  @fifo:		FIFO management structure.
  *  @timestamp:		interrupt timestamps.
+ *  @fifo:		FIFO management structure.
+ *  @buffer:		data transfer buffer aligned for DMA.
  */
 struct inv_icm42600_state {
 	struct mutex lock;
@@ -164,12 +164,12 @@ struct inv_icm42600_state {
 	struct inv_icm42600_suspended suspended;
 	struct iio_dev *indio_gyro;
 	struct iio_dev *indio_accel;
-	u8 buffer[2] __aligned(IIO_DMA_MINALIGN);
-	struct inv_icm42600_fifo fifo;
 	struct {
 		s64 gyro;
 		s64 accel;
 	} timestamp;
+	struct inv_icm42600_fifo fifo;
+	u8 buffer[2] __aligned(IIO_DMA_MINALIGN);
 };
 
 

-- 
2.49.0