incomplete in that the PRT routing was not aware of link programming.
Fix this by doing all routing through the link devices. The new algorithm
for setting up links is:
1. Read _CRS to get current setting. If invalid (not in _PRS), then set
to 0.
2. Attempt to call _DIS on the link. If successful, mark the link as not
routed. Otherwise, assume it still is.
Then when a routing request occurs:
3. Update weights for all IRQs
4. Attempt to route the initial IRQ if valid
5. If that fails, walk through the sorted list, attempting to route IRQs.
6. Configure the trigger/polarity based on _PRS.
Other changes:
* Add acpi_pci_find_prt() to look up the PRT entry for a given device and
acpi_pci_link_route() to select/route the best IRQ for it.
* Remove duplicated code in acpi_pcib_route_interrupt() that picked the
first IRQ from _PRS.
* Remove unneeded arguments from acpi_pcib_resume() and friends.
* Ignore _STA on link devices but report if it seems strange.
* Add a prt_source handle to the PRT structure since the ACPI struct
ACPI_PCI_ROUTING_TABLE uses a fixed-size entry for it. We'll need to
dynamically size this object if we want to use it the same way ACPI-CA
does. Null-terminate the source.
Tested by: Luo Hong <luohong99_at_mails.tsinghua.edu.cn>,
Jeffrey Katcher <jmkatcher_at_yahoo.com>
Info from: jhb, Len Brown (Intel)
e4116e931c