On Friday, 15 of August 2008, Stephen Hemminger wrote:
device_can_wakeup() returns 'true' if the device is capable of generating PME#
from at least one low power state (this is determined on the basis of the
contents of the device's PCI PM registers - please have a look at
drivers/pci/pci_pm_init() for details) or if ACPI tells us it can wake up.
IOW, the BIOSes opinion doesn't matter if we find that the device is capable of
generating PME#, so the regression must have been related to something else.
I'm very interested in the details, if available.
Of course, since we rely on the ability of the device to generate PME# and
device_can_wakeup() returning 'false' means that the device cannot generate
PME# from any state, it's reasonable to check it IMO.
Thanks,
Rafael
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