PNP: avoid legacy IDE IRQs
authorBjorn Helgaas <bjorn.helgaas@hp.com>
Fri, 27 Jun 2008 22:57:18 +0000 (16:57 -0600)
committerAndi Kleen <andi@basil.nowhere.org>
Wed, 16 Jul 2008 21:27:07 +0000 (23:27 +0200)
If an IDE controller is in compatibility mode, it expects to use
IRQs 14 and 15, so PNP should avoid them.

This patch should resolve this problem report:
  parallel driver grabs IRQ14 preventing legacy SFF ATA controller from working
  https://bugzilla.novell.com/show_bug.cgi?id=375836

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
drivers/pnp/resource.c

index d6388970a1a4cda8595717c5b03282e30fc6fafb..4cfe3a1efdfbc24a213abc838dab1631abf9f5d4 100644 (file)
@@ -286,6 +286,61 @@ static irqreturn_t pnp_test_handler(int irq, void *dev_id)
        return IRQ_HANDLED;
 }
 
+#ifdef CONFIG_PCI
+static int pci_dev_uses_irq(struct pnp_dev *pnp, struct pci_dev *pci,
+                           unsigned int irq)
+{
+       u32 class;
+       u8 progif;
+
+       if (pci->irq == irq) {
+               dev_dbg(&pnp->dev, "device %s using irq %d\n",
+                       pci_name(pci), irq);
+               return 1;
+       }
+
+       /*
+        * See pci_setup_device() and ata_pci_sff_activate_host() for
+        * similar IDE legacy detection.
+        */
+       pci_read_config_dword(pci, PCI_CLASS_REVISION, &class);
+       class >>= 8;            /* discard revision ID */
+       progif = class & 0xff;
+       class >>= 8;
+
+       if (class == PCI_CLASS_STORAGE_IDE) {
+               /*
+                * Unless both channels are native-PCI mode only,
+                * treat the compatibility IRQs as busy.
+                */
+               if ((progif & 0x5) != 0x5)
+                       if (pci_get_legacy_ide_irq(pci, 0) == irq ||
+                           pci_get_legacy_ide_irq(pci, 1) == irq) {
+                               dev_dbg(&pnp->dev, "legacy IDE device %s "
+                                       "using irq %d\n", pci_name(pci), irq);
+                               return 1;
+                       }
+       }
+
+       return 0;
+}
+#endif
+
+static int pci_uses_irq(struct pnp_dev *pnp, unsigned int irq)
+{
+#ifdef CONFIG_PCI
+       struct pci_dev *pci = NULL;
+
+       for_each_pci_dev(pci) {
+               if (pci_dev_uses_irq(pnp, pci, irq)) {
+                       pci_dev_put(pci);
+                       return 1;
+               }
+       }
+#endif
+       return 0;
+}
+
 int pnp_check_irq(struct pnp_dev *dev, struct resource *res)
 {
        int i;
@@ -317,18 +372,9 @@ int pnp_check_irq(struct pnp_dev *dev, struct resource *res)
                }
        }
 
-#ifdef CONFIG_PCI
        /* check if the resource is being used by a pci device */
-       {
-               struct pci_dev *pci = NULL;
-               for_each_pci_dev(pci) {
-                       if (pci->irq == *irq) {
-                               pci_dev_put(pci);
-                               return 0;
-                       }
-               }
-       }
-#endif
+       if (pci_uses_irq(dev, *irq))
+               return 0;
 
        /* check if the resource is already in use, skip if the
         * device is active because it itself may be in use */