From: Bjorn Helgaas <bjorn.helgaas@hp.com>
To: "Jesse Brandeburg" <jesse.brandeburg@gmail.com>
Subject: Re: de2104x: interrupts before interrupt handler is registered
Date: Wed, 8 Mar 2006 09:05:59 -0700
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Cc: "linux-os (Dick Johnson)" <linux-os@analogic.com>,
       "Robert Hancock" <hancockr@shaw.ca>,
       linux-kernel <linux-kernel@vger.kernel.org>
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On Wednesday 08 March 2006 01:18, Jesse Brandeburg wrote:
> On 3/7/06, Bjorn Helgaas <bjorn.helgaas@hp.com> 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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