Re: [PATCH 2/4] iio: imu: inv_icm42600: use 2 sensors fixed packet size of 16 bytes

[Jonathan Cameron <jic23@kernel.org>]

On Thu, 20 Aug 2026 21:02:38 +0200
Jean-Baptiste Maneyrol via B4 Relay <devnull+jean-baptiste.maneyrol.tdk.com@kernel.org> wrote:

> From: Jean-Baptiste Maneyrol <jean-baptiste.maneyrol@tdk.com>
> 
> Sometimes dynamic switch between 1 sensor frame to 2 sensors frame is
> not working when there are too much frames already in the FIFO. By
> moving accel/gyro on sleep before turning FIFO on, we are storing many
> FIFO frames before updating the frame format hitting the bug everytime.
> 
> Fix that by always using the 2 sensors frame of 16 bytes. Also update
> the hwfifo max watermark reported.
> 
> Signed-off-by: Jean-Baptiste Maneyrol <jean-baptiste.maneyrol@tdk.com>

So from that description this sometimes happens without the reorder?
If so is it appropriate to give this a Fixes tag?

> diff --git a/drivers/iio/imu/inv_icm42600/inv_icm42600_buffer.c b/drivers/iio/imu/inv_icm42600/inv_icm42600_buffer.c
> index 998d312f7bde..043ae9deee65 100644
> --- a/drivers/iio/imu/inv_icm42600/inv_icm42600_buffer.c
> +++ b/drivers/iio/imu/inv_icm42600/inv_icm42600_buffer.c
> @@ -131,13 +131,13 @@ int inv_icm42600_buffer_set_fifo_en(struct inv_icm42600_state *st,
>  		INV_ICM42600_FIFO_CONFIG1_GYRO_EN |
>  		INV_ICM42600_FIFO_CONFIG1_ACCEL_EN;
>  
> -	val = 0;
> -	if (fifo_en & INV_ICM42600_SENSOR_GYRO)
> -		val |= INV_ICM42600_FIFO_CONFIG1_GYRO_EN;
> -	if (fifo_en & INV_ICM42600_SENSOR_ACCEL)
> -		val |= INV_ICM42600_FIFO_CONFIG1_ACCEL_EN;
> -	if (fifo_en & INV_ICM42600_SENSOR_TEMP)
> -		val |= INV_ICM42600_FIFO_CONFIG1_TEMP_EN;
> +	/* always enable/disable all bits for allowing dynamic transitions */

This needs a little more.  It makes sense in the context of
this patch but will seem rather odd if we look at it sometime in
the distant future.  Dynamic transitions of what?

> +	if (fifo_en)
> +		val = INV_ICM42600_FIFO_CONFIG1_TEMP_EN |
> +		      INV_ICM42600_FIFO_CONFIG1_GYRO_EN |
> +		      INV_ICM42600_FIFO_CONFIG1_ACCEL_EN;
> +	else
> +		val = 0;
>  
>  	ret = regmap_update_bits(st->map, INV_ICM42600_REG_FIFO_CONFIG1, mask, val);
>  	if (ret)
> @@ -149,19 +149,6 @@ int inv_icm42600_buffer_set_fifo_en(struct inv_icm42600_state *st,
>  	return 0;
>  }