On Fri, 12 Nov 2010 13:18:41 +0000
Mark Brown <broonie@xxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
> On Fri, Nov 12, 2010 at 11:23:25AM +0200, Jarkko Nikula wrote:
>
> > Cross-device paths are registered by listing the widgets from device A in
> > a map for device B. An example below shows a path that connects MONO out of
> > A into Line In of B:
>
> > static const struct snd_soc_dapm_route mapA[] = {
> > {"MONO", NULL, "DAC"},
> > };
>
> > static const struct snd_soc_dapm_route mapB[] = {
> > {"Line In", NULL, "MONO"},
> > };
>
> This is going to fall over if we have widgets in two devices with the
> same name (and especially if we have two devices of the same kind in the
> system). Adding source device names to the paths would probably cover
> it with the same format but it should be considered and noted here.
>
That's the reason why the code favors a widget from current DAPM
context in snd_soc_dapm_add_route so that no current machine would
(hopefully) break because of this patch.
Of course any new code implementing cross-device paths between codecs
with conflicting widget names would need the name prefixing stuff also.
> > struct snd_soc_dapm_context {
> > - struct list_head widgets;
> > + int n_widgets; /* number of widgets in this context */
>
> I'm not sure why we need to count the number of widgets here;
>
True, this should go the next patch actually.
> > index 835087d..77be6b3 100644
> > --- a/include/sound/soc.h
> > +++ b/include/sound/soc.h
> > @@ -618,6 +618,7 @@ struct snd_soc_card {
> > struct list_head platform_dev_list;
> > struct list_head dai_dev_list;
> >
> > + struct list_head widgets;
> > struct list_head paths;
> >
>
> If we keep moving stuff into the card it's questionable what the context
> is buying us...
DAPM context represent the parent device (codecs currently and other
devices in someday) and its state so I don't see we'll be removing it in
near future even now the widgets and paths are moved to card.
--
Jarkko
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