PCI_CLASS_SERIAL_USB
#define IS_USB_DEVICE(pdev) ((pdev->class >> 8) == PCI_CLASS_SERIAL_USB)
PCI_CLASS_SERIAL_USB, 8, quirk_gpu_usb);
PCI_CLASS_SERIAL_USB, 8, quirk_gpu_usb);
.class = (PCI_CLASS_SERIAL_USB << 8),
.class = ((PCI_CLASS_SERIAL_USB << 8) | 0xfe),
PCI_CLASS_SERIAL_USB, 8, quirk_usb_early_handoff);