Re: [PATCH V11 3/9] iio: imu: inv_icm42607: Add inv_icm42607 Core Driver

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] Incorrect use of `regcache_sync()` in probe writes to the read-only WHOAMI register and executes before bus setup.
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commit 40cc0df3cdc00863249296cfd5a6b946f44cff13
Author: Chris Morgan <macromorgan@hotmail.com>

iio: imu: inv_icm42607: Add inv_icm42607 Core Driver

This commit adds the core component of a new inv_icm42607 driver. It includes
the initial setup functions and full register definitions for the device.

> diff --git a/drivers/iio/imu/inv_icm42607/inv_icm42607_core.c b/drivers/iio/imu/inv_icm42607/inv_icm42607_core.c
> --- /dev/null
> +++ b/drivers/iio/imu/inv_icm42607/inv_icm42607_core.c
[ ... ]
> +static int inv_icm42607_setup(struct inv_icm42607_state *st,
> +			      inv_icm42607_bus_setup inv_icm42607_bus_setup)
> +{
> +	const struct device *dev = regmap_get_device(st->map);
> +	unsigned int val;
> +	int ret;
> +
> +	ret = regmap_read(st->map, INV_ICM42607_REG_WHOAMI, &val);
> +	if (ret)
> +		return ret;
[ ... ]
> +	/* Sync the regcache again after a reset. */
> +	regcache_mark_dirty(st->map);
> +	ret = regcache_sync(st->map);
> +	if (ret)
> +		return ret;

[Severity: Medium]
Will regcache_sync() attempt to write the cached value back to the read-only
WHOAMI register here?

Since WHOAMI is read earlier in this function and is not marked as volatile in
inv_icm42607_regmap_config, its value is cached. Because the regmap_config
lacks a writeable_reg or wr_table definition, regmap assumes all non-volatile
registers are writable.

Could this unintended write to a read-only register cause a bus NACK or
unexpected hardware behavior, especially since it occurs before
inv_icm42607_bus_setup() configures bus-specific settings?

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Sashiko AI review · https://sashiko.dev/#/patchset/20260610175455.19006-1-macroalpha82@gmail.com?part=3