I mean RDRAND is a great example here, if you never use it, you never encounter these bugs. It's not impossible that PulseAudio tries to play higher quality audio or simply uses the device differently.
> I hope, that this particular group never ends up working on network hardware.
I'd kinda love it, probably quite a few fun hardware bugs will be found.
Pulseaudio mixes sound from several applications, unlike Alsa. Alsa just configures your soundcard for that one stream, Pulseaudio has no such luxury.
In order to mix relatively small buffers (because latency), it needs to do timing. If your soundcard has problem with timing (and many do!), you will get crackling. The good news is, that the problem with timing can be only at specific frequencies; in the past, I had a computer with Nvidia Ion and it did this with 44,1kHz audio. With 48kHz, everything was OK. So fixing the output at 48kHz by forcing Pulse to mix at this frequency fixed the crackling.
Dmix for alsa was buggy, because just like PA, it didn't know about quirks of the hardware out in the field. And it stayed buggy, because nobody used it in return. Yes, PA was forced on users, but in the result the quirks were found, implemented and today, we all are better off. I didn't have any problem with PA since 2012 or so, but quite enjoyed the features it brought to the desktop.
https://devblogs.microsoft.com/oldnewthing/20050512-48/?p=35...