lguest: fix comment style

[firefly-linux-kernel-4.4.55.git] / drivers / pci / pci.c

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index d5d6f5667d831bba610ea480a4635ef4a4612e42..dbd0f947f49728a3849f7e96b03a2de1f2ae180f 100644 (file)
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1517,11 +1517,20 @@ void pci_enable_ari(struct pci_dev *dev)
  *
  * Perform INTx swizzling for a device behind one level of bridge.  This is
  * required by section 9.1 of the PCI-to-PCI bridge specification for devices
- * behind bridges on add-in cards.
+ * behind bridges on add-in cards.  For devices with ARI enabled, the slot
+ * number is always 0 (see the Implementation Note in section 2.2.8.1 of
+ * the PCI Express Base Specification, Revision 2.1)
  */
 u8 pci_swizzle_interrupt_pin(struct pci_dev *dev, u8 pin)
 {
-       return (((pin - 1) + PCI_SLOT(dev->devfn)) % 4) + 1;
+       int slot;
+
+       if (pci_ari_enabled(dev->bus))
+               slot = 0;
+       else
+               slot = PCI_SLOT(dev->devfn);
+
+       return (((pin - 1) + slot) % 4) + 1;
 }
 
 int