Re: de2104x: interrupts before interrupt handler is registered

From: Bjorn Helgaas
Date: Wed Mar 08 2006 - 11:03:36 EST


On Wednesday 08 March 2006 01:18, Jesse Brandeburg wrote:
> On 3/7/06, Bjorn Helgaas <bjorn.helgaas@xxxxxx> wrote:
> > On Tuesday 07 March 2006 07:21, linux-os (Dick Johnson) wrote:
> > Maybe you could handle this with a PCI quirk that runs before
> > pci_enable_device(). IIRC, we considered exposing a separate
> > interface for PCI IRQ allocation and routing, but decided it
> > wasn't worth the complexity since so few devices would need it.
> >
> > > Linux-2.4.x had IRQs that were stable. One could put
> > > a handler in place that would handle the possible burst of interrupts
> > > upon startup. Then this was changed so the IRQ value is wrong
> > > until an unrelated and illogical event occurs.
> >
> > There are good reasons to wait to allocate the IRQ until you have
> > a driver that cares about the device. I'm sorry that this broke
> > your specific case.
>
> FWIW, I'd be interested in following up on something like this in
> another thread because e100 appears to have (at least in one
> reporter's dual e100 machine) a similar "hardware problem" where a
> shared interrupt line gets asserted too early and the kernel prints a
> Nobody Cared message.
>
> So we have a new way of doing things that exposes more broken
> hardware, shouldn't we provide a way for that hardware to continue
> working?

Booting with "pci=routeirq" gives the previous behavior.

It would be interesting to know whether that makes a difference
in the e100 issue you mention.
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