Re: [PATCH] ACPI, PCI: Get PRT entry during acpi_pci_enable_irq()

From: Yinghai Lu
Date: Fri Feb 15 2013 - 20:37:51 EST


On Fri, Feb 15, 2013 at 5:26 PM, Yinghai Lu <yinghai@xxxxxxxxxx> wrote:
> On Fri, Feb 15, 2013 at 4:39 PM, Bjorn Helgaas <bhelgaas@xxxxxxxxxx> wrote:
>> On Thu, Feb 14, 2013 at 5:50 PM, Yinghai Lu <yinghai@xxxxxxxxxx> wrote:
>>> On Tue, Feb 12, 2013 at 12:22 PM, Rafael J. Wysocki <rjw@xxxxxxx> wrote:
>>>> On Tuesday, February 12, 2013 11:11:23 AM 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@xxxxxxxxxxxxxxxxxx>
>>>>> Suggested-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
>>>>> Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
>>>>
>>>> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
>>>>
>>>>> ---
>>>>> drivers/acpi/pci_irq.c | 95 +++++++++++++++++---------------------------
>>>>> drivers/acpi/pci_root.c | 18 --------
>>>>> drivers/pci/pci-acpi.c | 24 -----------
>>>>> include/acpi/acpi_drivers.h | 5 --
>>>>> 4 files changed, 38 insertions(+), 104 deletions(-)
>>>
>>> Bjorn,
>>>
>>> Can you put this one into pci/next?
>>
>> I'm not sure what this patch is based on or what the best way to merge
>> it is. It doesn't apply cleanly to my next or
>> pci/yinghai-root-bus-hotplug branches.
>
> My fault, that is based on pci/next + pm/linux-next
>
> linux-next removed
> acpi_power_resource_(un)register_device ...
>
>>
>> I did apply it manually on top of pci/yinghai-root-bus-hotplug to try
>> it out, but we need to tweak the messages a little bit.
>>
>> Previously we printed "ACPI: PCI Interrupt Routing Table [%s._PRT]"
>> once when loading it, which was fine. Now we print it every time we
>> look at a _PRT, which is too much because it isn't really adding any
>> information.
>>
>> We also print "ACPI Exception: AE_NOT_FOUND, Evaluating _PRT
>> [AE_NOT_FOUND] (20121018/pci_irq-259)" if we find ACPI nodes without
>> _PRTs, which we shouldn't do, because that's a common and normal
>> situation.
>
> Sure. Can you have separated patch to do that ?
>
> Or want me to resend the patch.

Please check attached updated version that remove print out ...

and it could be applied cleanly on top of pci/yinghai-root-bus-hotplug

Thanks

Yinghai

Attachment: move_setup_prt_down_for_pci.patch
Description: Binary data