Re: [PATCH 2/6] PCI: acpiphp: enable_device(): rescan even if no newdevices on slot

[Bjorn Helgaas]

On Thu, Jun 27, 2013 at 10:32 AM, Mika Westerberg
<mika.westerberg@xxxxxxxxxxxxxxx> wrote:
> On Thu, Jun 27, 2013 at 04:02:29PM +0300, Mika Westerberg wrote:
>> On Wed, Jun 26, 2013 at 05:37:58PM -0600, Bjorn Helgaas wrote:
>> > > @@ -707,8 +702,11 @@ static int __ref enable_device(struct acpiphp_slot *slot)
>> > >                             dev->hdr_type == PCI_HEADER_TYPE_CARDBUS) {
>> > >                                 max = pci_scan_bridge(bus, dev, max, pass);
>> > >                                 if (pass && dev->subordinate) {
>> > > -                                       check_hotplug_bridge(slot, dev);
>> > > -                                       pcibios_resource_survey_bus(dev->subordinate);
>> > > +                                       if (!dev->subordinate->is_added) {
>> > > +                                               check_hotplug_bridge(slot, dev);
>> > > +                                               pcibios_resource_survey_bus(
>> > > +                                                       dev->subordinate);
>> >
>> > It's a shame that pcibios_resource_survey_bus() can't be called twice.
>> >  It would be nice if it were smart enough to notice on the second call
>> > that "oh, resources have already been assigned, so there's nothing
>> > more to be done."  Did you look to see whether that's feasible?
>>
>> I didn't but now that you mentioned I went and checked. I'm pretty sure we
>> can handle it there in the next revision and drop this change.
>
> With following patch that fixes pcibios_resource_survey_bus() Thunderbolt
> seems to be working just fine (and the quirk is gone).
>
> If it looks okay, I'll include it into the next iteration of the patches.

That looks great, thanks a lot for exploring this!

> diff --git a/arch/x86/pci/i386.c b/arch/x86/pci/i386.c
> index 94919e3..db6b1ab 100644
> --- a/arch/x86/pci/i386.c
> +++ b/arch/x86/pci/i386.c
> @@ -210,6 +210,8 @@ static void pcibios_allocate_bridge_resources(struct pci_dev *dev)
>                 r = &dev->resource[idx];
>                 if (!r->flags)
>                         continue;
> +               if (r->parent)  /* Already allocated */
> +                       continue;
>                 if (!r->start || pci_claim_resource(dev, idx) < 0) {
>                         /*
>                          * Something is wrong with the region.
> @@ -318,6 +320,8 @@ static void pcibios_allocate_dev_rom_resource(struct pci_dev *dev)
>         r = &dev->resource[PCI_ROM_RESOURCE];
>         if (!r->flags || !r->start)
>                 return;
> +       if (r->parent) /* Already allocated */
> +               return;
>
>         if (pci_claim_resource(dev, PCI_ROM_RESOURCE) < 0) {
>                 r->end -= r->start;
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