Interesting. So, on top of, I presume, whatever DSP you get from the sound chipset/SoC, there could be other layers of DSP throughout the hardware too. That seems like a real pain in the ass, to be honest. (Though personally I'd really prefer something that protects the voice coils from overheating to be in hardware at least, if nothing else.)
(I still do genuinely wonder what's going on inside of SOF on modern Intel laptops, too. That's not separate from the chipset and I don't think it gets tuned for specific laptop acoustics. So what does that do?)
Phoenix APU presentation talk about DSP for dropping processing into input/output of audio (quite probably including things like turning an array of microphones into single source, etc.)
Having recently looked for new laptop, they often have firmware loaded by driver on windows into DSP or sound chain, sometimes even to enable half of the speakers you need to custom load firmware on Linux which apparently includes DSP code that adapts stereo signal for multiple speakers with different parameters.
(I still do genuinely wonder what's going on inside of SOF on modern Intel laptops, too. That's not separate from the chipset and I don't think it gets tuned for specific laptop acoustics. So what does that do?)