Re: [PATCH v3 4/7] iio: core: Add cleanup.h support for iio_device_claim_*()

David Lechner
2026-01-18T19:30:14Z

On 1/18/26 9:23 AM, Kurt Borja wrote:
> On Fri Jan 16, 2026 at 5:03 PM -05, David Lechner wrote:
>> On 1/6/26 2:06 AM, Kurt Borja wrote:
>>> Add guard classes for iio_device_claim_*() conditional locks. This will
>>> aid drivers write safer and cleaner code when dealing with some common
>>> patterns.
>>>
>>> These classes are not meant to be used directly by drivers (hence the
>>> __priv__ prefix). Instead, documented wrapper macros are provided to
>>> enforce the use of ACQUIRE() or guard() semantics and avoid the
>>> problematic scoped guard.
>>>
>>> Suggested-by: Andy Shevchenko <andriy.shevchenko@intel.com>
>>> Signed-off-by: Kurt Borja <kuurtb@gmail.com>
>>> ---
>>> include/linux/iio/iio.h | 71 +++++++++++++++++++++++++++++++++++++++++++++++++
>>> 1 file changed, 71 insertions(+)
>>>
>>> diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h
>>> index d8af0456f966..c795f731f2d8 100644
>>> --- a/include/linux/iio/iio.h
>>> +++ b/include/linux/iio/iio.h
>>> @@ -10,6 +10,7 @@
>>> #include <linux/align.h>
>>> #include <linux/device.h>
>>> #include <linux/cdev.h>
>>> +#include <linux/cleanup.h>
>>> #include <linux/compiler_types.h>
>>> #include <linux/minmax.h>
>>> #include <linux/slab.h>
>>> @@ -740,6 +741,76 @@ static inline bool iio_device_try_claim_buffer_mode(struct iio_dev *indio_dev)
>>> */
>>> #define iio_device_release_buffer_mode(indio_dev) __iio_dev_mode_unlock(indio_dev)
>>>
>>> +/*
>>> + * These classes are not meant to be used directly by drivers (hence the
>>> + * __priv__ prefix). Instead, documented wrapper macros are provided bellow to
>>> + * enforce the use of ACQUIRE() or guard() semantics and avoid the problematic
>>> + * scoped guard variants.
>>> + */
>>> +DEFINE_GUARD(__priv__iio_dev_mode_lock, struct iio_dev *,
>>> + __iio_dev_mode_lock(_T), __iio_dev_mode_unlock(_T));
>>> +DEFINE_GUARD_COND(__priv__iio_dev_mode_lock, _try_direct,
>>> + iio_device_claim_direct(_T));
>>> +
>>> +/**
>>> + * IIO_DEV_ACQUIRE_DIRECT_MODE(_dev, _var) - Tries to acquire the direct mode
>>> + * lock with automatic release
>>
>> I don't think it is usual to put the function parameters in the
>> doc comment like this. They don't match the actual names anyway.
>
> Hi David,
>
> This format of kernel-doc applies to function-like macros too [1]. I'll
> match the name of the variables though.

Right. And it has no parameters between the () on the first line
in that documentation.

/*
* function_name() - Brief description of function.

So it should be just `IIO_DEV_ACQUIRE_DIRECT_MODE() - ...

>
>> + * @dev: IIO device instance
>> + * @claim: Variable identifier to store acquire result
>> + *

The parameters go below like this, which is already correct.