From: Theodore Ts'o (tytso@athena.mit.edu)
Date: 06/28/93


From: Theodore Ts'o <tytso@athena.mit.edu>
Subject: Re: "Wild Interrupt" / Soundblaster problem
Date: 28 Jun 1993 23:59:32 -0400


   From: bsa@kf8nh.wariat.org (Brandon S. Allbery)
   Date: Tue, 29 Jun 1993 00:05:49 GMT

   In article <20nivg$2ii@senator-bedfellow.MIT.EDU> tytso@athena.mit.edu writes:
> I am running 0.99pl9 and encounter the message "Wild Interrupt? (IRQ7)"
> during the boot sequence.
>This message means that you have a cheap motherboard, and somewhere,
>some RF-generated interference occasionally causes one of your interrupt
>lines on your bus to float for a microsecond. The interrupt controller

   Um, Ted? This may not be strictly related, but it's possible to get
   a "Wild interrupt?" on the IRQ of a bus mouse if you load a mouse
   driver under DOS, then later warm-boot into Linux --- since DOS
   doesn't have a shutdown procedure, if the mouse is activated (by the
   mouse driver) it can send a spurious interrupt (generally from being
   moved at some point during the reboot) which will be detected by
   Linux before the Linux busmouse driver hooks the interrupt and
   reconfigures the mouse.

This is true; however, in this person's case, he had removed all
possible cards which might have used IRQ 7. While a wild interrupt can
certainly be caused by some device which is causing interrupts at random
times, such as an DOS-initialized mouse, wild interrupts on IRQ *7* when
there are no other explainable boards which might be causing the
interrupt can be caused by problem I mentioned above.

                                                        - Ted