Re: Strange EHCI/OHCI IRQ and other PCI errors on boot with 2.6.32(which 2.6.26 did not see) on Geode LX/CS5536.

From: Alan Stern
Date: Wed Jan 20 2010 - 17:07:06 EST


On Wed, 20 Jan 2010, Lennart Sorensen wrote:

> On Wed, Jan 20, 2010 at 03:20:46PM -0500, Alan Stern wrote:
> > Okay, this means that something else is affecting the IRQ line.
>
> Yep. I went and disabled irq5 on the LPC bus, and that didn't help.
>
> > > Interestingly the number of interrupts listed in /proc/interrupts is
> > > exactly 300000.
> >
> > That's probably because the kernel disabled the IRQ after 100000
> > unhandled interrupts, and re-enabled it each time a new device was
> > registered for that IRQ.
>
> Certainly seems to be the case.
>
> > Or you could just stop using USB on the old box. :-)
>
> Well I just tried another box, and same thing.
>
> If I boot with 'irqpoll' then everything seems fine.
>
> Any idea how I can figure out why irqpoll makes it happy? Does it give
> any reports anywhere about misrouted irqs?

Not that I know of.

Does 2.6.26 fail on the new machine?

Are you using a .config different from the one that used to work with
2.6.26?

Alan Stern

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