Re: [PATCH v9 8/9] regulator: Add MediaTek MT6392 regulator

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] Data race and global state corruption due to dynamic mutation of static global `regulator_desc` array during asynchronous probe.
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commit 986be7d1279b96c61669e064178dad0c9c317fcd
Author: Fabien Parent <parent.f@gmail.com>

regulator: Add MediaTek MT6392 regulator

This commit introduces the regulator driver for the MediaTek MT6392 PMIC.
The PMIC is used on boards based on MT8167, MT8516, and other SoCs,
connecting via SPI wrapped inside PWRAP.

> diff --git a/drivers/regulator/mt6392-regulator.c b/drivers/regulator/mt6392-regulator.c
> new file mode 100644
> index 0000000000000..93fe887709c3b
> --- /dev/null
> +++ b/drivers/regulator/mt6392-regulator.c

[ ... ]

> +static int mt6392_set_buck_vsel_reg(struct platform_device *pdev)
> +{
> +	struct mt6397_chip *mt6392 = dev_get_drvdata(pdev->dev.parent);
> +	int i;
> +	u32 regval;
> +
> +	for (i = 0; i < MT6392_MAX_REGULATOR; i++) {
> +		if (mt6392_regulators[i].vselctrl_reg) {
> +			// Read the vselctrl_reg register
> +			if (regmap_read(mt6392->regmap,
> +					mt6392_regulators[i].vselctrl_reg,
> +					&regval) < 0) {
> +				dev_err(&pdev->dev,
> +					"Failed to read buck ctrl\n");
> +				return -EIO;
> +			}
> +
> +			// vselctrl_reg[vselctrl_mask] defines the mode
> +			if (regval & mt6392_regulators[i].vselctrl_mask) {
> +				// Regulator in Normal mode
> +				mt6392_regulators[i].desc.vsel_reg =
> +					mt6392_regulators[i].vsel_normal_mode_reg;
> +				mt6392_regulators[i].desc.vsel_mask =
> +					mt6392_regulators[i].vsel_normal_mode_mask;

[Severity: High]
Does this code safely handle concurrent probes or multiple device instances?

The mt6392_regulators array is a static global variable. Modifying
desc.vsel_reg and desc.vsel_mask directly during probe alters shared global
state.

The regulator core API expects regulator_desc to be a constant immutable
structure, as devm_regulator_register() takes a const pointer. Mutating
this static structure can corrupt the active configuration of previously
registered instances, or persist corrupted state across unbind/rebind cycles.

> +			} else {
> +				// Regulator in Register mode
> +				mt6392_regulators[i].desc.vsel_reg =
> +					mt6392_regulators[i].vsel_reg_mode_reg;
> +				mt6392_regulators[i].desc.vsel_mask =
> +					mt6392_regulators[i].vsel_reg_mode_mask;
> +			}
> +		}
> +	}
> +
> +	return 0;
> +}

[ ... ]

> +static struct platform_driver mt6392_regulator_driver = {
> +	.driver = {
> +		.name = "mt6392-regulator",
> +		.probe_type = PROBE_PREFER_ASYNCHRONOUS,

[Severity: High]
Could this asynchronous probe type lead to a data race?

Since multiple device instances could be probed concurrently, they would
race to modify the shared static mt6392_regulators array during
mt6392_set_buck_vsel_reg().

> +	},
> +	.probe = mt6392_regulator_probe,
> +	.id_table = mt6392_platform_ids,
> +};

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260621081634.467858-1-l.scorcia@gmail.com?part=8