From mboxrd@z Thu Jan  1 00:00:00 1970
From: Peter Hurley <peter@hurleysoftware.com>
Subject: Re: [PATCH] ACPI, PCI: Get PRT entry during acpi_pci_enable_irq()
Date: Tue, 12 Feb 2013 21:20:10 -0500
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References: <CAE9FiQUkmnV_On5+ZpH2pF4Li1HxLpkO8bp4TnYB46=pc9Safg@mail.gmail.com>
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To: Yinghai Lu <yinghai@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>, "Rafael J. Wysocki" <rjw@sisk.pl>, linux-pci@vger.kernel.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org
List-Id: linux-acpi@vger.kernel.org

On Tue, 2013-02-12 at 11:11 -0800, Yinghai Lu wrote:
> Peter Hurley found "irq 18 nobody cared" with pci-next, and dmesg has
> 
> [    8.983246] pci 0000:00:1e.0: can't derive routing for PCI INT A
> [    8.983600] snd_ctxfi 0000:09:02.0: PCI INT A: no GSI - using ISA IRQ 5
> 
> bisect to
> | commit 4f535093cf8f6da8cfda7c36c2c1ecd2e9586ee4
> |     PCI: Put pci_dev in device tree as early as possible
> 
> It turns out we need to call acpi_pci_irq_add_prt() after the pci bridges
> are scanned.
> 
> Bjorn said:
>  The bus number binding means acpi_pci_irq_add_prt() has to happen
>  after enumerating everything below a bridge, and it will prevent us
>  from doing any bus number reassignment for hotplug.
> 
>  I think we should remove the bus numbers from the cached _PRT (or
>  maybe even remove the _PRT caching completely).  When we enable a PCI
>  device's IRQ, we should search up the PCI device tree looking for a
>  _PRT associated with each node, and applying normal PCI bridge
>  swizzling when we don't find a _PRT.  I think this can be done without
>  using PCI bus numbers at all.
> 
> So here we try to remove _PRT caching completely.
> 
> -v2: check !handle early.
> 
> Reported-and-tested-by: Peter Hurley <peter@hurleysoftware.com>

Actually true now :)

Reported-and-tested-by: Peter Hurley <peter@hurleysoftware.com>

Regards and thanks again,
Peter Hurley

PS - I just happened to see this version on the list. Would you please
cc me on any future versions?