PME# for add-on cards

Rafael J. Wysocki
2009-08-23T23:12:39Z

Hi,

Recently we've had a bug report indicating that WoL doesn't work with e100,
although the driver does everything needed to support it. Apparently, the user
had to echo PCI0 to /proc/acpi/wakeup to make it work.

After some debugging it turned out that PCI0 is the PCI host bridge
(no-bus:pci0000:00), so apparently echoing PCI0 to /proc/acpi/wakeup causes
a wake-up GPE to be set up for the host bridge which triggers wake-up once
eth0 signals PME#.

So, it looks like we need to set up wake-up GPE for a host bridge for PME#
from add-on cards to work, at least on this particular box.

First, I wonder if that's the case in general (anybody knows?). Second, if
that is the case, would it be a good idea to set up the host bridge wake-up GPE
by default?

Rafael