On Thu, 20 Aug 2015, Jiang Liu wrote: > On 2015/8/20 17:15, Thomas Gleixner wrote: > > On Thu, 20 Aug 2015, Jiang Liu wrote: > >> When converting to hierarchical irqdomain, the IOAPIC > >> internal and interfaces have changed much, and seems no easy > >> way to revert cd68f6bd53cf. There may be three possible solutions > >> here: > >> 1) use quirk to correct SCI polarity, as the patch does. > >> 2) change IOAPIC interfaces to provide a special way to > >> handle SCI interrupt. > >> 3) change drivers/acpi/pci_link.c to penalize SCI IRQ so it > >> won't be used for PCI IRQ if SCI polarity conflicts with > >> PCI IRQ polarity. > > > > Stupid question. Is the SCI polarity ever the opposite of PCI > > polarity? I.e. is such a ACPI override valid at all? > Hi Thomas, > I have analyzed another system which works: > 1) SCI(IRQ9) works in level, high mode (so such an ACPI override is valid) > 2) there's a flag to detect whether system works in PIC or APIC mode. > 3) IRQ9 may be used for PCI IRQ if system works in PIC mode. Why? > 4) IRQ9 won't be used for PCI IRQ if system works in APIC mode. > Based on the above observation, I feel solution 3) may be the best one. Can you whip up a patch and test it on hyperv and maybe other machines which have that SCI override. Thanks tglx -- 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
