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Jiang Liu authored
commit 5d0ddfeb upstream. Nick Meier reported a regression with HyperV that " After rebooting the VM, the following messages are logged in syslog when trying to load the tulip driver: tulip: Linux Tulip drivers version 1.1.15 (Feb 27, 2007) tulip: 0000:00:0a.0: PCI INT A: failed to register GSI tulip: Cannot enable tulip board #0, aborting tulip: probe of 0000:00:0a.0 failed with error -16 Errors occur in 3.19.0 kernel Works in 3.17 kernel. " According to the ACPI dump file posted by Nick at https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1440072 The ACPI MADT table includes an interrupt source overridden entry for ACPI SCI: [236h 0566 1] Subtable Type : 02 <Interrupt Source Override> [237h 0567 1] Length : 0A [238h 0568 1] Bus : 00 [239h 0569 1] Source : 09 [23Ah 0570 4] Interrupt : 00000009 [23Eh 0574 2] Flags (decoded below) : 000D Polarity : 1 Trigger Mode : 3 And in DSDT table, we have _PRT method to define PCI interrupts, which eventually goes to: Name (PRSA, ResourceTemplate () { IRQ (Level, ActiveLow, Shared, ) {3,4,5,7,9,10,11,12,14,15} }) Name (PRSB, ResourceTemplate () { IRQ (Level, ActiveLow, Shared, ) {3,4,5,7,9,10,11,12,14,15} }) Name (PRSC, ResourceTemplate () { IRQ (Level, ActiveLow, Shared, ) {3,4,5,7,9,10,11,12,14,15} }) Name (PRSD, ResourceTemplate () { IRQ (Level, ActiveLow, Shared, ) {3,4,5,7,9,10,11,12,14,15} }) According to the MADT and DSDT tables, IRQ 9 may be used for: 1) ACPI SCI in level, high mode 2) PCI legacy IRQ in level, low mode So there's a conflict in polarity setting for IRQ 9. Prior to commit cd68f6bd ("x86, irq, acpi: Get rid of special handling of GSI for ACPI SCI"), ACPI SCI is handled specially and there's no check for conflicts between ACPI SCI and PCI legagy IRQ. And it seems that the HyperV hypervisor doesn't make use of the polarity configuration in IOAPIC entry, so it just works. Commit cd68f6bd gets rid of the specially handling of ACPI SCI, and then the pin attribute checking code discloses the conflicts between ACPI SCI and PCI legacy IRQ on HyperV virtual machine, and rejects the request to assign IRQ9 to PCI devices. So penalize legacy IRQ used by ACPI SCI and mark it unusable if ACPI SCI attributes conflict with PCI IRQ attributes. Please refer to following links for more information: https://bugzilla.kernel.org/show_bug.cgi?id=101301 https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1440072 Fixes: cd68f6bd ("x86, irq, acpi: Get rid of special handling of GSI for ACPI SCI") Reported-and-tested-by: Nick Meier <nmeier@microsoft.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Kamal Mostafa <kamal@canonical.com>
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