PME while runtime suspend

Hi Bjorn,

Trying to support runtime suspend in a driver, which puts the device
in D3hot and wait either for host/driver initiated resume
(runtime_get), or device initiated resume (PME).

But, given that old change: 42eca2302146 ("PCI: Don't touch card regs
after runtime suspend D3")

PME that was enabled from pci_finish_runtime_suspend() is not enabled
anymore for almost all drivers in case of runtime-suspend. The only
way to enable this is by calling pci_wake_from_d3() from the PCI device
driver's runtime_suspend() callback, but this function fails if the
device wake_up is not enabled, which makes sense since it targets
system-wide sleep wake-up (and wake-up is user/distro policy).

So is there a proper way to allow PME while the device is runtime
suspended, without having to tell the user to enabled 'unrelated' wake_up
capability?

Regards,
Loic