Re: [alsa-devel] [RFC PATCH 1/2] regmap: add configurable lock class key for lockdep

[Lars-Peter Clausen <lars@metafoo.de>]

On 06/30/2015 06:56 AM, Nicolas Boichat wrote:
> On Mon, Jun 29, 2015 at 04:34:11PM +0100, Mark Brown wrote:
>> On Mon, Jun 29, 2015 at 04:18:11PM +0200, Lars-Peter Clausen wrote:
>>> Leaves us pretty much with only two options. Either add a lock key pointer
>>> to regmap_config which needs to be manually initialized. Or wrap all
>>> regmap_init() variants to create a static lock key. I'd slightly prefer the
>>> later. We can avoid most of the boiler-plate code by using some helper
>>> macros to generate the wrappers.
>>
>> It's better to keep the bodges in the core, yes.
>
> Partial attempt below. Of course all other _init functions will need to be
> converted as well. I'd like to get feedback before I do the rest of the work.

Looks good to me.

> The macro part is quite repetitive and I don't think it can be simplified.

How about something like

#ifdef CONFIG_LOCKDEP

#define regmap_lockdep_wrapper(fn, ...)				\
(								\
	({							\
		static struct lock_class_key _key;		\
		fn(__VA_ARGS__,	&_key,				\
			KBUILD_BASENAME ":"			\
			__stringify(__LINE__) ":"		\
			"(" #config ")->_lock");		\
	})							\
)

#else
#define regmap_lockdep_wrapper(fn, ...) fn(__VA_ARGS__, NULL, NULL)
#endif

#define regmap_init_i2c(i2c, config) \
	regmap_lockdep_wrapper(__regmap_init_i2c, i2c, config)
...