[patch 27/28] PNP: avoid legacy IDE IRQs

Bjorn Helgaas
2008-06-27T23:12:38Z

[-- Attachment #1: pnp-legacy-ide-irq --]
[-- Type: text/plain, Size: 2421 bytes --]

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>

Index: work14/drivers/pnp/resource.c
===================================================================
--- work14.orig/drivers/pnp/resource.c 2008-06-17 16:40:04.000000000 -0600
+++ work14/drivers/pnp/resource.c 2008-06-24 15:39:08.000000000 -0600
@@ -286,6 +286,61 @@ static irqreturn_t pnp_test_handler(int
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, s
}
}

-#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 */

--