Re: [PATCH V12 6/9] iio: imu: inv_icm42607: Add Temp Support in icm42607

[Jonathan Cameron <jic23@kernel.org>]

On Thu, 11 Jun 2026 15:26:03 -0500
Chris Morgan <macroalpha82@gmail.com> wrote:

> From: Chris Morgan <macromorgan@hotmail.com>
> 
> Add functions for reading temperature sensor data.
> 
> Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
The buffer isn't safe for use for DMA.  See below.
I'm not sure I'd have noticed. This used to be a common bug but not seen it that
often recently for some reason!

Jonathan

  
> ---
>  drivers/iio/imu/inv_icm42607/Makefile         |  1 +
>  drivers/iio/imu/inv_icm42607/inv_icm42607.h   |  5 ++
>  .../iio/imu/inv_icm42607/inv_icm42607_core.c  | 18 +++++
>  .../iio/imu/inv_icm42607/inv_icm42607_temp.c  | 76 +++++++++++++++++++
>  .../iio/imu/inv_icm42607/inv_icm42607_temp.h  | 37 +++++++++
>  5 files changed, 137 insertions(+)
>  create mode 100644 drivers/iio/imu/inv_icm42607/inv_icm42607_temp.c
>  create mode 100644 drivers/iio/imu/inv_icm42607/inv_icm42607_temp.h
> 
> diff --git a/drivers/iio/imu/inv_icm42607/Makefile b/drivers/iio/imu/inv_icm42607/Makefile
> index be109102e203..c04953ed42ce 100644
> --- a/drivers/iio/imu/inv_icm42607/Makefile
> +++ b/drivers/iio/imu/inv_icm42607/Makefile
> @@ -2,6 +2,7 @@
>  
>  obj-$(CONFIG_INV_ICM42607) += inv-icm42607.o
>  inv-icm42607-y += inv_icm42607_core.o
> +inv-icm42607-y += inv_icm42607_temp.o
>  
>  obj-$(CONFIG_INV_ICM42607_I2C) += inv-icm42607-i2c.o
>  inv-icm42607-i2c-y += inv_icm42607_i2c.o
> diff --git a/drivers/iio/imu/inv_icm42607/inv_icm42607.h b/drivers/iio/imu/inv_icm42607/inv_icm42607.h
> index 28edc12d5373..53dd23509a53 100644
> --- a/drivers/iio/imu/inv_icm42607/inv_icm42607.h
> +++ b/drivers/iio/imu/inv_icm42607/inv_icm42607.h
> @@ -114,6 +114,7 @@ struct inv_icm42607_suspended {
>  
>  /**
>   *  struct inv_icm42607_state - driver state variables
> + *  @buffer:		data transfer buffer aligned for DMA.
>   *  @hw:		Hardware specific data.
>   *  @map:		regmap pointer.
>   *  @vddio_supply:	I/O voltage regulator for the chip.
> @@ -124,6 +125,7 @@ struct inv_icm42607_suspended {
>   *  @orientation:	sensor chip orientation relative to main hardware.
>   */
>  struct inv_icm42607_state {
> +	__be16 buffer[3] __aligned(IIO_DMA_MINALIGN);

Look in more depth at what this does.   Key thing is there is a reason
this should always be at the end of the iio_priv() structure.

(Sashiko caught this btw)

>  	const struct inv_icm42607_hw *hw;
>  	struct regmap *map;
>  	struct regulator *vddio_supply;
> @@ -363,6 +365,9 @@ extern const struct inv_icm42607_hw inv_icm42607_hw_data;
>  extern const struct inv_icm42607_hw inv_icm42607p_hw_data;
>  extern const struct dev_pm_ops inv_icm42607_pm_ops;
>