Debugging hard hang/IRQ problems (advice needed) [es1370/es1371]

Bob McElrath (mcelrath@draal.physics.wisc.edu)
Mon, 8 Mar 1999 12:55:21 -0600 (CST)

I'm trying to fix the es1370/es1371 driver (both OSS and ALSA) for Alpha.
The problem is that when trying to do PCM audio, the kernel hangs hard, and
the audio output is a continous buzzing. I've narrowed it down to the
IRQ/DMA code. I can prevent it from crashing by NOT enabling audio output
(commenting out the line that tells the card to start playing), and when
output is enabled, I know that the IRQ handler does get called immediately
before it crashes. Commenting out the entire IRQ handler, and even
de-registering the IRQ handler have no effect on the behaviour.

I've run out of ideas to try, and I need some advice on how to tackle such a
problem. As far as I know there is no way to step through an interrupt
handler, and I have nothing like a fancy PCI bus analyzer to help me. If
anyone who has successfully debugged an interrupt/DMA related problem like
this for drivers, I'd REALLY appreciate any advice you can offer. Links,
HOWTO's, offers for a PCI analyzer... ;)

TIA,
-- Bob

Bob McElrath (rsmcelrath@students.wisc.edu) Univ. of Wisconsin at Madison

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/