[alsa-devel] [PATCH] ASoC: dpcm: prevent error for paths including static links

[Charles Keepax]

On Wed, Mar 30, 2016 at 10:27:02AM -0700, Mark Brown wrote:
> On Wed, Mar 30, 2016 at 06:13:14PM +0100, Charles Keepax wrote:
> > On Wed, Mar 30, 2016 at 09:36:50AM -0700, Mark Brown wrote:
> 
> > > Doesn't this mean that the appropriate fix is to terminate the DPCM
> > > routing at the first back end DAI so we're not trying to DPCM outside
> > > the SoC?
> 
> > I think (not 100% certain) you can have multiple backends
> > connected to a single front end, which makes it hard to know when
> > to stop or even if it is assured that all the backends will be
> > before any other spurious DAIs in the widget list.
> 
> You can have multiple backends connected but they shouldn't be chained
> together, they should be connected in parallel.  We can tell if we're
> walking a node that's a backend, why would we walk the graph beyond
> that?

Ah ok apologies, I misunderstood your suggestion. I
thought you meant aborting the widget list search in
dpcm_add_paths, but you actually mean aborting the graph walk in
snd_soc_dapm_dai_get_connnected_widgets. That looks totally like
it would work, although it needs a bit of thought as I guess the
original intention was for get_connected_widgets to be pretty
generic, but it does only have the single user.

I will get Piotr to have a look at respinning the patch, when he
returns.

Thanks,
Charles