On Wednesday 12 March 2008, Bjorn Helgaas wrote: > On Tuesday 11 March 2008 09:40:04 pm Len Brown wrote: > > Thanks for following up on these, Bjorn. > > > > Is it true that simply enabling pci=routeirq on these boxes > > is an insufficient workaround? > > > > I suspect the answer is yes, because when pci=routeirq works > > we may just be lucky -- eg. we happen to assign the real > > and the fake link to the same IRQ and thus the driver > > actually registers for the correct IRQ, but by accident. > > I double-checked this, and your guess is correct. On the MD9580 > laptop, the BIOS reports 00:09[A] is connected to LNKA, which we > assign to IRQ 10: > > ACPI: PCI Interrupt 0000:00:09.0[A] -> Link [LNKA] -> GSI 10 (level, low) -> IRQ 10 > > The device is actually connected to LNKB, which we also assigned > to IRQ 10 (before my patch, we only enable LNKB with pci=routeirq > because it's used by 00:06, for which we don't have a driver): > > ACPI: PCI Interrupt 0000:00:06.0[A] -> Link [LNKB] -> GSI 10 (level, low) -> IRQ 10 > > Similarly, on the Dell OptiPlex, we set both LNKA and LNKB to IRQ 10. > The 00:0d[A] line is connected to LNKA, but the BIOS reports it on > LNKB. Without pci=routeirq, we may not enable LNKA because it's > only used by 01:00[A], which is a VGA device. Thanks, Bjorn. This again raises suspicion that Windows doesn't disable and then re-enable PCI interrupt links. It is probably just using them in-place. While we disable them at boot and re-enable at probe b/c it fixed some spurious interrupt issues -- it may be that those issues were IOAPIC mode issues and for PIC systems we should do something different, such as not touch the links at all. -Len -- 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
