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

From: Arjan van de Ven
Date: Mon Jun 29 2015 - 10:35:33 EST


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?)


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/