Re: [PATCH v4 4/5] iio: imu: inv_icm42607: Implement MREGx register access

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] iio: missing BLK_SEL state restoration on error path
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commit 73a51c00960ea7003bf6f6db7c54135d8950eb5e
Author: Kanak Shilledar <kanak.shilledar@axis.com>

iio: imu: inv_icm42607: Implement MREGx register access

This commit implements indirect register access for the MREGx banks in the
ICM42607 driver. It adds routines for bank switching via the BLK_SEL registers,
applying the required bus delays, and restoring direct access.

> diff --git a/drivers/iio/imu/inv_icm42607/inv_icm42607_core.c b/drivers/iio/imu/inv_icm42607/inv_icm42607_core.c
> index 114e7afcda391..9d572b3ffb15b 100644
> --- a/drivers/iio/imu/inv_icm42607/inv_icm42607_core.c
> +++ b/drivers/iio/imu/inv_icm42607/inv_icm42607_core.c

[ ... ]

> +static int inv_icm42607_mreg_read(struct regmap *map, unsigned int reg,
> +				  u8 *data, size_t count)
> +{

[ ... ]

> +	ret = regmap_write(map, INV_ICM42607_REG_BLK_SEL_R, blk_sel);
> +	if (ret)
> +		goto out;
> +
> +	ret = regmap_write(map, INV_ICM42607_REG_MADDR_R,
> +			   FIELD_GET(INV_ICM42607_REG_ADDR_MASK, reg));
> +	if (ret)
> +		goto out;

[Severity: Medium]
If this regmap_write() fails, the code jumps to out without restoring
INV_ICM42607_REG_BLK_SEL_R to 0.

Does this leave the device locked in indirect access mode if a transient
I2C error occurs here, and turn a recoverable error into a persistent device
failure by corrupting subsequent standard register operations?

[ ... ]

> +static int inv_icm42607_mreg_write(struct regmap *map, unsigned int reg,
> +				   const u8 *data, size_t count)
> +{

[ ... ]

> +	ret = regmap_write(map, INV_ICM42607_REG_MADDR_W,
> +			   FIELD_GET(INV_ICM42607_REG_ADDR_MASK, reg));
> +	if (ret)
> +		goto out;
> +
> +	ret = regmap_write(map, INV_ICM42607_REG_M_W, *data);
> +	if (ret)
> +		goto out;

[Severity: Medium]
Similarly in inv_icm42607_mreg_write(), if writing to INV_ICM42607_REG_M_W
fails, the function jumps to out.

Could this also skip the BLK_SEL_W restoration and risk leaving the device in
an incorrect bank state?

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Sashiko AI review · https://sashiko.dev/#/patchset/20260917-b4-inv_icm42370p-v4-0-fd9373f123c9@axis.com?part=4