Comment 7 for bug 280646

This looks relevant:

http://osdir.com/ml/linux.acpi.ibm-acpi.devel/2007-10/msg00102.html

Recent Lenovo ThinkPads define a dummy grahpics device, find it and ignore it

Those laptops define one grahpics device on a PCI Express (e.g. Internal Intel
965 card) and one on a separate PCI bus (via a PCI root bridge, e.g. in AGP
case for an Nvidia graphics card).
PCI devices need to be enumerated and checked whether on the ACPI video device
a graphics card is really connected to.

This patch only checks whether a PCI device exists (could also be a PCI bridge).
To really get the pci_dev struct and check it whether it really is of class
"graphics card" or to further make use of it in this driver, it must be checked
what got set up behind a possilbe bridge.

Signed-off-by: Thomas Renninger <trenn@xxxxxxx>