Hi Kuninori,
there seems to be a problem in the simple-card using the following device tree fragment:
sound { compatible = "simple-audio-card"; simple-audio-card,format = "i2s"; [snip] simple-audio-card,bitclock-master = <&dailink0_master>; simple-audio-card,frame-master = <&dailink0_master>;
simple-audio-card,cpu@0 { sound-dai = <&sai6>; };
simple-audio-card,cpu@1 { sound-dai = <&sai5>; };
dailink0_master: simple-audio-card,codec { sound-dai = <&wm8904>; }; };
Just for the background, I have hardware with the LS1028A which only have unidirectional SAIs. But two of those SAIs (one for playback and one for capture) are connected to one codec (with a shared bit and frame clock).
So I thought the example in the simple-card bindings makes sense for my case. Although I don't really know what "(Mixing)" means.
Nevertheless, using the fragment above, the kernel oopses or fails to probe the hardware. I've traced that back to the following: - the count is correct: the kernel reports "link 2, dais 3, ccnf 0". please note the 3 dais here. - but simple_dai_link_of() will always "allocate" two dais from the pool:
cpu_dai = dai_props->cpu_dai = &priv->dais[li->dais++]; codec_dai = dai_props->codec_dai = &priv->dais[li->dais++];
While this still works for the first link, the second one will fail because codec_dai will not be valid.
Btw, converting that to two explicit dai-link nodes, the dai count will be 4 and it will work.
Is my use case correct or should I use the two explicit dai-link nodes? But in any case there seems to be a bug in simple-card.
-michael