Hello,

> >>So I guess everything on the USB card ( 3xOHCI, 1x EHCI ) should share the
> >>same virq, but the audio card >should get a different one.
> > 
> > 
> > It seems to me that devices with different IPL levels shouldn't share
> > virqs, too.
> 
> The levels blocked by intr_calcmasks() is the union of the IPL levels of
> all devices sharing the IRQ.  Sharing an IRQ between an audio and a USB
> device would be particularly bad: USB is supposed to be at a low priority
> (IPL_USB == IPL_BIO), but this device gets elevated to IPL_AUDIO.  Even
> worse, any code running at IPL_BIO would block the shared IRQ, so the audio
> interrupt will experience high latency.

Hmm, naive thought: what if we wouldn't OR the IPLs of a given IRQ but instead put all on the same level, IPL_AUDIO in this case? This would give the USB code undue priority but it should reduce the confusion.

have fun
Michael