Re: [PATCH v4 2/2] iio: light: add AS7343 multi-spectral sensor driver

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] Hardware state leak on error path leaves REG_BANK set, potentially breaking subsequent probe attempts.
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commit 72a91926280c648f27572174db691cdd7cd7fa33
Author: Chang Yu <marcus.yu.56@gmail.com>

iio: light: add AS7343 multi-spectral sensor driver

Add a driver for the AMS AS7343 14-channel multi-spectral sensor.
The driver exposes 12 spectral channels via sysfs and implements
runtime PM to stop measurements when suspended.

> diff --git a/drivers/iio/light/as7343.c b/drivers/iio/light/as7343.c
> new file mode 100644
> index 0000000000000..9ea6a44c35b92
> --- /dev/null
> +++ b/drivers/iio/light/as7343.c
[ ... ]
> +static int as7343_setup_device(struct device *dev, struct as7343_data *data)
> +{
> +	struct regmap *map = data->regmap;
> +	unsigned int val;
> +	__le16 step;
> +	int ret;
> +
> +	/* Power on */
> +	ret = regmap_set_bits(map, AS7343_ENABLE, AS7343_ENABLE_PON);
> +	if (ret)
> +		return ret;
> +
> +	/* Need to set REG_BANK to 1 before we can access ID */
> +	ret = regmap_set_bits(map, AS7343_CFG0, AS7343_CFG0_REG_BANK);
> +	if (ret)
> +		return ret;
> +
> +	ret = regmap_read(map, AS7343_ID, &val);
> +	if (ret)
> +		return ret;

[Severity: Medium]
If regmap_read() fails here due to a transient I2C error, the function returns
early without clearing the AS7343_CFG0_REG_BANK bit.

Since the device is left in bank 1, and power might not be cut on probe
failure (for example, if the vdd regulator is shared or a dummy regulator),
could this cause subsequent probe attempts or deferred probes to fail because
the hardware is in an unexpected state?

> +
> +	if (val != 0x81)
> +		dev_info(dev, "Unknown device ID: %x\n", val);
> +
> +	ret = regmap_clear_bits(map, AS7343_CFG0, AS7343_CFG0_REG_BANK);
> +	if (ret)
> +		return ret;
[ ... ]

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Sashiko AI review · https://sashiko.dev/#/patchset/20260912013912.51887-1-marcus.yu.56@gmail.com?part=2