Re: [PATCH RFC 5/6] iio: health: max30102: Use cleanup.h for IIO locks

[Kurt Borja]

On Thu Dec 4, 2025 at 12:35 PM -05, David Lechner wrote:
> On 12/4/25 11:07 AM, Kurt Borja wrote:
>> On Wed Dec 3, 2025 at 4:52 PM -05, David Lechner wrote:
>>> On 12/3/25 1:18 PM, Kurt Borja wrote:
>
> ...
>
>>> I would write the whole function like this:
>>>
>>> static int max30102_read_raw(struct iio_dev *indio_dev,
>>> 			     struct iio_chan_spec const *chan,
>>> 			     int *val, int *val2, long mask)
>>> {
>>> 	struct max30102_data *data = iio_priv(indio_dev);
>>> 	int ret;
>>>
>>> 	switch (mask) {
>>> 	case IIO_CHAN_INFO_RAW: {
>>> 		/*
>>> 		 * Temperature reading can only be acquired when not in
>>> 		 * shutdown; leave shutdown briefly when buffer not running
>>> 		 */
>>> 		guard(iio_device_claim)(indio_dev);
>> 
>> AFAIK you can't guard() inside switch-case blocks. I don't know the
>> exact reason, but it has to be scoped_guard().
>
> You can. You just need the braces like I showed in my suggestion.
>
> The reason is that guard() is declaring local variables and some
> compilers like LLVM don't like declaring local variables in a
> switch case. By adding the { } scope, the variables are limited
> to that scope and the issue goes away.

Ah - You're right. I dind't see the braces.

Now it is overly complicated. In this case I see why guard() isn't
really an improvement.


-- 
 ~ Kurt