o Do not mask the RX overrun interrupt.
o Rewrite em_intr():
- Axe EM_MAX_INTR.
- Cycle acknowledging interrupts and processing
packets until zero interrupt cause register is
read.
- If RX overrun comes in log this fact. [ NetBSD also
resets adapter in this case, but my tests showed that
this is not needed and only pessimizes behavior under
heavy load. ]
- Since almost all functions is rewritten, style the
remaining lines.
This fixes em(4) interfaces wedging under high load.
In collaboration with: wpaul, cognet
Obtained from: NetBSD