One other thing. This might help narrow down the location in the code where it happens. I might have mentioned this before, but I'll repeat it for clarity:

I can make this happen with only the kernel installed (no custom init), the pop happens sometime while my custom logo is up on the screen.

But when I do have a custom init, it goes like this:

1) Boots and mounts the drives.

2) Presents a menu allowing me to choose whether voladj is off or on.

3) Depending on what I pressed, it sends the ioctl message to either activate or deactivate voladj.

4) Pauses for about 3-5 seconds and waits for a "q" on the serial port.

5) If no "q" on the serial port, then launch the player.

Okay, I get the pop at step 3. So it happens somewhere in the code that responds to the ioctl message. It's not related to the player, since the player software hasn't started yet, and won't start for the next few seconds.

But I also get the pop if I don't do an ioctl at all with no custom init. So it happens somewhere in the code that gets called by the kernel as the player is booting.

So what kernel code is called both during the regular boot process and when the ioctl message is received?



___________
Tony Fabris