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

[Arjan van de Ven]

On 6/29/2015 7:22 AM, Mark Brown wrote:
> On Mon, Jun 29, 2015 at 10:03:09PM +0800, Nicolas Boichat wrote:
>
>> regmap instances are kalloc'ed, so they cannot contain the
>> lock_class_key, which needs to be statically allocated (in .data).
>> Another option would be to preallocate a bunch of lock_class_key in
>> regmap.c, and pick from that, but that's terribly hacky...
>
> Honestly this is all starting to sound like we're having to jump through
> too many hoops for lockep (and other APIs are too from the sounds of it)
> so we should be looking at lockdep here.

lockdep assumes that there is a known lock hierarchy, at least known
to the developer.

seems like for regmap there isn't

(I would be interested to know how you avoid ABBA deadlocks btw,
can you have 2 devices, one with a hierarchy one way, and another
with the hierarchy the other way?)