On Tue, Nov 1, 2011 at 11:33 AM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote:
>
> And xHCI certainly shouldn't be affected by something happening to the
> Ethernet controller.
So what about the PCI bridges? If the PME event makes it from the
device to the bridge (I have no idea what the signalling is), and the
*bridge* does the PME handling, we do that
if (pci_dev->subordinate)
pci_pme_wakeup_bus(pci_dev->subordinate);
thing. I didn't look how recursive it is and just what it does, but it
strikes me that depending on just how deep the PME event goes, it
might explain the "any PME event causes ehci issues".
One thing that is special about the EHCI device is that we seem to use
ACPI to manage the D0/D3 transition for it. Don't ask me why, but
that's what the messages certainly imply. Maybe the "native PCI" stuff
is smart enough to know that "Hey, there's no event for me, so I'll
not do anything", but then the ehci/acpi interaction means that the
ehci controllers get woken up for everything.
But what do I know? Certainly not PCI PM crud.
Linus
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