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| author | Alex Williamson <alex.williamson@redhat.com> | 2015-05-26 15:11:51 -0600 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2015-05-30 20:47:35 -0500 |
| commit | 917bfd93d3c9c644743940deaf8fe0cff77947eb (patch) | |
| tree | 15e0198c1a418778dd6f0d4453fd974dfbed5f08 | |
| parent | 19bdb6e4ec071bc49a9871b41e6a59a1657ed365 (diff) | |
| download | linux-917bfd93d3c9c644743940deaf8fe0cff77947eb.tar.bz2 | |
ACPI / PCI: Account for ARI in _PRT lookups
The PCIe specification, rev 3.0, section 2.2.8.1, contains the following
implementation note:
Virtual Wire Mapping for INTx Interrupts From ARI Devices
The implied Device Number for an ARI Device is 0. When ARI-aware
software (including BIOS and operating system) enables ARI Forwarding in
the Downstream Port immediately above an ARI Device in order to access
its Extended Functions, software must comprehend that the Downstream Port
will use Device Number 0 for the virtual wire mappings of INTx interrupts
coming from all Functions of the ARI Device. If non-ARI-aware software
attempts to determine the virtual wire mappings for Extended Functions,
it can come up with incorrect mappings by examining the traditional
Device Number field and finding it to be non-0.
We account for this in pci_swizzle_interrupt_pin(), but it looks like we
miss it here, looking for a _PRT entry with a slot matching the ARI device
slot number. This can cause errors like:
pcieport 0000:80:03.0: can't derive routing for PCI INT B
sfc 0000:82:01.1: PCI INT B: no GSI
pci_dev.irq is then invalid, resulting in errors for drivers that attempt
to enable INTx on the device. Fix by using slot 0 for ARI enabled devices.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Don Dutile <ddutile@redhat.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| -rw-r--r-- | drivers/acpi/pci_irq.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/acpi/pci_irq.c b/drivers/acpi/pci_irq.c index b1def411c0b8..4db10b189104 100644 --- a/drivers/acpi/pci_irq.c +++ b/drivers/acpi/pci_irq.c @@ -163,7 +163,7 @@ static int acpi_pci_irq_check_entry(acpi_handle handle, struct pci_dev *dev, { int segment = pci_domain_nr(dev->bus); int bus = dev->bus->number; - int device = PCI_SLOT(dev->devfn); + int device = pci_ari_enabled(dev->bus) ? 0 : PCI_SLOT(dev->devfn); struct acpi_prt_entry *entry; if (((prt->address >> 16) & 0xffff) != device || |