Re: [bug report] iio: light: isl29018: Replace a variant of iio_get_acpi_device_name_and_data()

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

On Wed, Oct 30, 2024 at 12:53:57PM +0300, Dan Carpenter wrote:
> Hello Andy Shevchenko,
> 
> Commit 14686836fb69 ("iio: light: isl29018: Replace a variant of
> iio_get_acpi_device_name_and_data()") from Oct 24, 2024 (linux-next),
> leads to the following Smatch static checker warning:
> 
>     drivers/iio/light/isl29018.c:724 isl29018_probe() error: uninitialized symbol 'ddata'.
>     drivers/iio/light/ltr501.c:1514 ltr501_probe() error: uninitialized symbol 'ddata'.
> 
> drivers/iio/light/isl29018.c
>     701 static int isl29018_probe(struct i2c_client *client)
>     702 {
>     703         const struct i2c_device_id *id = i2c_client_get_device_id(client);
>     704         struct isl29018_chip *chip;
>     705         struct iio_dev *indio_dev;
>     706         const void *ddata;
>     707         const char *name;
>     708         int dev_id;
>     709         int err;
>     710 
>     711         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
>     712         if (!indio_dev)
>     713                 return -ENOMEM;
>     714 
>     715         chip = iio_priv(indio_dev);
>     716 
>     717         i2c_set_clientdata(client, indio_dev);
>     718 
>     719         if (id) {
>     720                 name = id->name;
>     721                 dev_id = id->driver_data;
>     722         } else {
>     723                 name = iio_get_acpi_device_name_and_data(&client->dev, &ddata);
> --> 724                 dev_id = (intptr_t)ddata;
> 
> How do we know that iio_get_acpi_device_name_and_data() will succeed?

Ideally we need to file &ddata with NULL in such case, but it will be
equal to 0, so it only works with the chip_info in place.

Let me look into this once more, thanks for the good catch!

>     725         }
>     726 
>     727         mutex_init(&chip->lock);
>     728 
>     729         chip->type = dev_id;

-- 
With Best Regards,
Andy Shevchenko