Re: [PATCH v2 2/3] hwmon: (emc1403) Convert to use OF bindings

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] Ambiguous OF match data value (0) prevents error handling for unsupported devices.
--

commit 7ef40c1ea161b005037b0b33a8e16b1f9bf6d41a
Author: Jonas Schwöbel <jonasschwoebel@yahoo.de>

hwmon: (emc1403) Convert to use OF bindings

This commit adds an OF match compatible table to the emc1403 driver
to enable device tree support.

> --- a/drivers/hwmon/emc1403.c
> +++ b/drivers/hwmon/emc1403.c
[ ... ]
> @@ -659,14 +660,14 @@ static int emc1403_probe(struct i2c_client *client)
[ ... ]
> -	data->chip = id->driver_data;
> +	data->chip = (uintptr_t)i2c_get_match_data(client);
> +

[Severity: Medium]
Will this cast silently hide error conditions?

If an unsupported device is manually bound via sysfs, i2c_get_match_data()
will return NULL (no match found). Since emc1402 evaluates to 0 in the
emc1403_chip enum, casting NULL to uintptr_t assigns 0 to data->chip. This
causes the driver to proceed as if an emc1402 device was found, rather than
safely aborting and returning -ENODEV.

[ ... ]
> @@ -682,10 +683,21 @@ static const unsigned short emc1403_address_list[] = {
[ ... ]
> +static const struct of_device_id emc1403_of_match[] = {
> +	{ .compatible = "smsc,emc1402", .data = (void *)emc1402 },
> +	{ .compatible = "smsc,emc1403", .data = (void *)emc1403 },

[Severity: Medium]
Does assigning 0 as the match data here cause ambiguity during device matching?

Because emc1402 is 0, when device_get_match_data() matches "smsc,emc1402",
it returns NULL. This forces i2c_get_match_data() to fall back to
i2c_match_id().

While this happens to succeed for valid DT nodes because the I2C core strips
the vendor prefix (allowing the id_table to match), it removes the ability
to distinguish between a successful emc1402 match and an error where no
match was found at all.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260619103153.216444-1-clamor95@gmail.com?part=2