[PATCH v2 19/27] pci: PCIe driver for Marvell Armada 370/XP systems

[Bjorn Helgaas]

On Thu, Jan 31, 2013 at 9:33 AM, Thomas Petazzoni
<thomas.petazzoni at free-electrons.com> wrote:
> Dear Bjorn Helgaas,
>
> On Thu, 31 Jan 2013 09:30:07 -0700, Bjorn Helgaas wrote:
>
>> > Following you're recommendation, I've changed this, and left those
>> > values initialized to 0 by default, in order to let Linux set correct
>> > values. Yes, Linux does assign appropriate values in the Secondary Bus
>> > Number Register. But before that Linux also complains loudly that the
>> > bridge configuration is invalid:
>> >
>> > pci 0000:00:01.0: bridge configuration invalid ([bus 00-00]), reconfiguring
>> > pci 0000:00:02.0: bridge configuration invalid ([bus 00-00]), reconfiguring
>> > pci 0000:00:03.0: bridge configuration invalid ([bus 00-00]), reconfiguring
>> > pci 0000:00:04.0: bridge configuration invalid ([bus 00-00]), reconfiguring
>> > pci 0000:00:05.0: bridge configuration invalid ([bus 00-00]), reconfiguring
>> > pci 0000:00:06.0: bridge configuration invalid ([bus 00-00]), reconfiguring
>>
>> Linux makes the unwarranted assumption that the PCI hierarchy has
>> already been configured by firmware.  If the only problem is the
>> messages above, I think we could just rework the message so it doesn't
>> look like an error.  I would guess that we probably also see the same
>> distressing message when we hot-add a card with a bridge on it,
>> because firmware won't have initialized the bridge.
>>
>> My rule of thumb is that I like to note something in dmesg about the
>> initial configuration of bus/mem/io apertures and BARs, as well as
>> indications when we update them.  That way, the dmesg log should
>> contain enough information to debug most enumeration and configuration
>> defects.  pci_scan_bridge() is somewhat lacking in this regard.
>
> Ok. Would something like:
>
>  "bridge configuration with unassigned bus numbers ([bus 00-00]), reconfiguring"
>
> be an acceptable to replace this one?

Seems reasonable.