I've previously posted under ALSA's user mailing list so to avoid the clutter, the details about what's happening is here: http://article.gmane.org/gmane.linux.alsa.user/38258 http://article.gmane.org/gmane.linux.alsa.user/38260
There was no debug info under /proc/asound/card0/ so nothing to give from there unless you guys need something specific.
Output of alsa-debug.sh: http://www.alsa-project.org/db/?f=26187faadd47f3626029ba667cb004e74695f2b2
https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/commit/sound/pc...
Seem cannot read valid value from register within three trials
state.CMI8738 { control.1 { iface PCM device 2 name 'Playback Channel Map' value.0 0 value.1 0 value.2 0 value.3 0 value.4 0 value.5 0 comment { access read type INTEGER count 6 range '0 - 36' } }
Seem bug in adding channel map to iec958 instead of analog
https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/commit/sound/pc...
pcm.!default { type plug slave.pcm "dmixer" }
You need asym plugin for playback and capture when overwrite pcm.default