[alsa-devel] [PATCH] ASoC: Suppress restore of default register values for rbtree cache sync

[Mark Brown]

On Mon, Jun 06, 2011 at 10:18:07AM +0100, Dimitris Papastamos wrote:

> There should be a check for reg_def_copy being NULL, the soc-cache code
> is also built around the idea that the driver might not provide a
> register defaults cache at all so this change needs to cope with that.

Hrm, at this point I'm rather inclined to say that if you're using a
fancy cache method you should be providing defaults.

> Also I'd expect the reg_def_copy cache to be freed sooner rather than
> while unregistering the codec, this is not happening at the moment,
> which is wasting significant space.  This is the case because it is only
> used during initialization.

That's the bit I was saying at the bottom of the commit message about
putting it into the node itself; since we're currently never freeing it
we can use it but we should really be copying it into the tree.  The
memory wasted is a *much* less severe problem than the I/O bandwidth
consumed rewriting the entire register map on every sync.