[alsa-devel] Question about patch ASoC: Prevent components from being bound to multiple cards

[Koro Chen]

On Mon, 2015-10-05 at 11:07 +0100, Mark Brown wrote:
> On Sat, Oct 03, 2015 at 11:01:40PM +0800, Koro Chen wrote:
> > On Fri, 2015-10-02 at 15:48 +0100, Mark Brown wrote:
> > > On Fri, Oct 02, 2015 at 06:34:24PM +0800, Koro Chen wrote:
> 
> > > > I have two cards originally but the second one failed because of the
> > > > patch ASoC: Prevent components from being bound to multiple cards.
> 
> > > > My configuration is like this:
> > > > card0: use platform's DAI component A
> > > > card1: use the same platform's DAI component B
> 
> > > What do you mean by "DAI component" here?  It's not a term I'm familiar
> > > with...
> 
> > Sorry I didn't make myself clear enough. In the
> > sound/soc/mediatek/mtk-afe-pcm.c, I register two components
> > "mtk_afe_pcm_dai_component" and "mtk_afe_hdmi_dai_component", each has
> > its corresponding DAIs. Card0 (which is mt8173-rt5676-rt5650.c) uses
> > DAIs from the first component, and card1 (new) uses DAIs of the second
> > component. These two components are probed successfully and separately
> > by card0 and card1, but card1 failed to probe another component created
> > by snd_soc_register_platform(), which is already bound to card0.
> 
> OK, I see.  We probably do want to relax that restriction, it makes more
> sense at the DAI level but at the component level when we have
> components that have a bunch of independant DAIs hanging off a DMA
> controler as one component (which does make sense) then it breaks.
Thanks for your suggestion. Is it make sense if we use
component->registered_as_component, which is only true in case of
snd_soc_register_component() and will be false for components created by
snd_soc_register_platform() or snd_soc_register_codec(), then modify the
check condition like this:

@@ -1102,11 +1102,12 @@ static int soc_probe_component(struct
snd_soc_card *card,
        struct snd_soc_dai *dai;
        int ret;

        if (!strcmp(component->name, "snd-soc-dummy"))
                return 0;

        if (component->card) {
-               if (component->card != card) {
+               if (component->card != card &&
component->registered_as_component) {