Stray irq 7's

[Douglas W. Goodall]

I am a very knowlegeable OS software engineer and I know the stray irq7
problem intimately.

The PIC (programable interrupt controller) used in PCs is sensitive and will
raise an IR7 interrupt without a valid cause. This has been going on since
S100 systems. We used to call it the vacuum cleaner interrupt because just
about anything can cause it.

The only fix for it is to enhance the source code of the interrupt routine
to accept the interrupt and scrub the PIC.

The problem is documented in the Intel publications. I have the same problem
with my Sharp PC-MM20.
You have two choices.  See if you can ignore the problem, if it doesn't
occur too often. Or encourage the FreeBSD
Engineers to add the required code to the interrupt code.  Or do it
yourself. The PIC is complicated though and
if you place it in the wrong mode, things will not work correctly.

Douglas W. Goodall
Long term FreeBSD supporter