Hi Konrad, We have found the root cause with your great support. If BIOS assigns an IRQ number for a PCI device, acpi_pci_irq_enable() fails to assign IOAPIC IRQ then due to the check: if (dev->irq > 0) return 0; For a quick workaround, just comment out above check. But we need some time to figure out a clean fixup for it. We will send out new version once it gets resolved. Thanks for your great help again. Regards! Gerry On 2014/7/16 0:10, Konrad Rzeszutek Wilk wrote: > already assigned IRQ -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html