There is still a downside to this patch: if the user inserts a VIA
PCI card into a VIA-based motherboard, in some circumstances the
quirk will also run on
the VIA PCI card. This corner case is hard to avoid.
NAK
This is not a "corner case"
Very large numbers of VIA mainboards ship with some of the VIA devices
built in and some of them on the PCI bus. In fact they generally start
shipped on the board as PCI devices and migrate over time.
If they are on the V-Bus then the IRQ number controls routing if they
are on the PCI bus the IRQ line controls routing as normal.
OK, so per your last mail, most VIA devices start on the PCI bus and
then later are migrated onto the V-bus.
Devices on the PCI bus need to be quirked (in some circumstances), as
when they are on the PCI bus they use the IRQ line for routing, and
the IRQ line is what the quirk actually modifies.
V-bus devices do not need the quirk because IRQ routing there is
handled by IRQ number alone.
Is the above correct?
I've no idea.