[net.periphs] device interrupts during config

mcm@ncsu.UUCP (Mike Mitchell) (04/06/84)

We have just installed a new line printer interface on our VAX 11/780
running 4.1 BSD.  The new controller presents a constant interrupt
if interrupts are enabled & the printer is ready to accept a character.
During auto-configure, interrupts are enabled and the system goes into
a tight loop trying to dismiss the interrupt.  Has anyone seen this
problem before?  I've fixed the problem by setting the priority to zero
before the probe routine is called and modifying locore.s so that during
autoconfigure stray interrupts return with the old priority set to the
level of the interrupting device.  This allows only one interrupt per
device, even if the interrupt line is held.

I find it strange that the line printer driver has a comment that it
has been fixed to support interfaces that interrupt constantly, yet
the autoconfigure code breaks when a device interrupts constantly.

	Mike Mitchell
	mcnc!ncsu!mcm

cdl@mplvax.UUCP (04/07/84)

|
If that were my line-printer controller that presented continuous
interrupt requests to the bus I would do my best to send it back
and get some other kind.  It's *broken* according to the bus spec.

	Carl Lowenstein		Marine Physical Lab., U.C. San Diego
		{ucbvax,philabs}!sdcsvax!mplvax!cdl