The plugins for the DSP under ALSA seem to be there, but I wonder if this is related to the maemo recorder / gstream that seems to disable the mic, then reenables it after some unknown something happens.

Update: aplay and arecord (given the right sample format) work fine. Sometimes. But I haven't got the flash program to find the linux microphone. If it is requesting an unsupported sampling rate (and slow is bad here), it won't work, at least not unless I fidget with the plugin to decimate.