Re: 2.6.2-rc3: irq#19 - nobody cared - with an au88xx

[Daniel Jacobowitz <dan@debian.org>]

On Tue, Apr 06, 2004 at 02:02:38PM -0400, Daniel Jacobowitz wrote:
> I still haven't figured out which kernel first introduced the problem,
> but it's still present, at 2.6.5.  I didn't see it while I was running
> 2.6.3-rc3, for some reason.
> 
> Now I'm using the ALSA au8830 driver.  There was no output from the
> driver before the nobody-cared message, so it was caused by one of
> these (sound/pci/au88x0/au88x0_core.c):
> 
>         //check if the interrupt is ours.
>         if (!(hwread(vortex->mmio, VORTEX_STAT) & 0x1))
>                 return IRQ_NONE;

It's this one.  If I wait until it locks up - it did at exactly 600,001
interrupts, interesting... then reload the module with this:
        //check if the interrupt is ours.
        if (!(hwread(vortex->mmio, VORTEX_STAT) & 0x1))
{
		printk ("vortex: Interrupt not ours\n");
                return IRQ_NONE;
}

I get _exactly_ 100,000 copies of that printout, and then the interrupt
is disabled with a 'nobody cares' response.  The first time, all
100,000 were on CPU0; the second time, 2 were on CPU0 and the other
99,998 on CPU1.

So it looks as if something gets wedged, and then the interrupt fires
continuously for no reason.

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer