1 files changed, 8 insertions, 7 deletions

diff --git a/drivers/acpi/pci_irq.c b/drivers/acpi/pci_irq.c
index 5ce1fcf77455..2c52cf0004ba 100644
--- a/drivers/acpi/pci_irq.c
+++ b/drivers/acpi/pci_irq.c
@@ -62,7 +62,7 @@ static DEFINE_SPINLOCK(acpi_prt_lock);
 
 static inline char pin_name(int pin)
 {
-        return 'A' + pin;
+        return 'A' + pin - 1;
 }
 
 /* --------------------------------------------------------------------------
@@ -203,10 +203,15 @@ acpi_pci_irq_add_entry(acpi_handle handle,
         if (!entry)
                 return -ENOMEM;
 
+        /*
+         * Note that the _PRT uses 0=INTA, 1=INTB, etc, while PCI uses
+         * 1=INTA, 2=INTB.  We use the PCI encoding throughout, so convert
+         * it here.
+         */
         entry->id.segment = segment;
         entry->id.bus = bus;
         entry->id.device = (prt->address >> 16) & 0xFFFF;
-        entry->pin = prt->pin;
+        entry->pin = prt->pin + 1;
 
         do_prt_fixups(entry, prt);
 
@@ -425,7 +430,7 @@ acpi_pci_irq_derive(struct pci_dev *dev,
          * PCI interrupt routing entry (eg. yenta bridge and add-in card bridge).
          */
         while (irq < 0 && bridge->bus->self) {
-                pin = (pin + PCI_SLOT(bridge->devfn)) % 4;
+                pin = (((pin - 1) + PCI_SLOT(bridge->devfn)) % 4) + 1;
                 bridge = bridge->bus->self;
 
                 if ((bridge->class >> 8) == PCI_CLASS_BRIDGE_CARDBUS) {
@@ -437,8 +442,6 @@ acpi_pci_irq_derive(struct pci_dev *dev,
                                                   pci_name(bridge)));
                                 return -1;
                         }
-                        /* Pin is from 0 to 3 */
-                        bridge_pin--;
                         pin = bridge_pin;
                 }
 
@@ -483,7 +486,6 @@ int acpi_pci_irq_enable(struct pci_dev *dev)
                                   pci_name(dev)));
                 return 0;
         }
-        pin--;
 
         /* 
          * First we check the PCI IRQ routing table (PRT) for an IRQ.  PRT
@@ -566,7 +568,6 @@ void acpi_pci_irq_disable(struct pci_dev *dev)
         pin = dev->pin;
         if (!pin)
                 return;
-        pin--;
 
         /*
          * First we check the PCI IRQ routing table (PRT) for an IRQ.