[alsa-devel] [PATCH 2/4] ASoC: soc-cache: Add support for flat register caching

Mark Brown broonie at opensource.wolfsonmicro.com
Fri Nov 5 14:31:44 CET 2010

On Fri, Nov 05, 2010 at 09:34:37AM +0000, Dimitris Papastamos wrote:
> On Thu, 2010-11-04 at 14:31 -0400, Mark Brown wrote:

> > > +	mutex_init(&cache_rw_mutex);
> > > +

> > I'd kind of expect this to be with the other cache setup?

> Do you mean that the mutex should also be used with the other caching
> techniques?  That is not needed because we currently lock at a higher
> level, in the function that delegates the calls to the implementation
> functions.

I'd expect this to be with the rest of the initialisation for the
structure that it's embedded in - having this be initialised in this
place separately to anything else feels wrong.  Of course at the minute
it's not in a structure (which I raised as an issue as well IIRC) which
means that we'll have an issue with multiple initialisation if two
devices are registered.

> > Are you sure that all the CODECs that rely on the existing shared
> > register cache are going to call this?

> What do you mean by 'shared register cache'?  Each codec gets its own
> copy of their register cache.

The shared register cache support code.

> Any CODEC driver that calls snd_soc_register_codec() and has provided
> reg_cache_size and reg_word_size will have soc-core setting up its cache
> accordingly.  By default the provided snd_soc_codec_driver is zero-ed
> out, so its compress_type will default to the flat compression type.

Are you absolutely positive that every user of the code is using a
register cache initialised using that method?

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