[alsa-devel] [PATCH 2/4] ASoC: soc-cache: Add support for flat register caching
dp at opensource.wolfsonmicro.com
Fri Nov 5 15:12:00 CET 2010
On Fri, 2010-11-05 at 10:07 -0400, Mark Brown wrote:
> On Fri, Nov 05, 2010 at 01:59:51PM +0000, Dimitris Papastamos wrote:
> > On Fri, 2010-11-05 at 09:31 -0400, Mark Brown wrote:
> > > Are you absolutely positive that every user of the code is using a
> > > register cache initialised using that method?
> > If people don't want to use our caching API, then if they need so they
> > will have to manage that locally somewhere in the driver code. In that
> > scenario, they will not call snd_soc_codec_set_cache_io() and they will
> > have to set the codec->read() and codec->write() to point to their own
> > implementation. They should also not set reg_cache_size and
> > reg_word_size.
> My concern is that since nothing stops people mix'n'matching currently
> someone may be using one bit and not the other - we need to audit all
> the current drivers to make sure that nothing is going to explode.
> > The previous caching code had the same issue. If someone called
> > snd_soc_codec_set_cache_io() and they had not provided a valid
> > reg_cache_size and reg_word_size (both of them were zero), the
> > underlying codec->reg_cache would have been NULL and therefore any
> > read()/write() operations going through soc-cache.c would result
> > in an invalid access.
> They could be setting these up later, or otherwise initialising. It's
> likely that nobody is but it's ringing an alarm bell that we need to
> audit in case there's something that's going to bite us later on.
Yup sure, it'd be wise to audit the codecs for any invalid use of the
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