From: ANdy Grover <agrover@groveronline.com>
This is a cleanup of pirq_enable_irq. I couldn't understand this function
easily so I cleaned it up.
- Hoisted Via quirk to top -- shouldn't break anything but who knows -
can someone with this chipset test?
- Hoisted legacy IDE check too.
- Reduced indenting, added comments.
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/arch/i386/pci/irq.c | 108 ++++++++++++++++++++++----------------------
1 files changed, 56 insertions(+), 52 deletions(-)
diff -puN arch/i386/pci/irq.c~pirq_enable_irq-cleanup arch/i386/pci/irq.c
--- 25/arch/i386/pci/irq.c~pirq_enable_irq-cleanup Wed Aug 4 16:17:42 2004
+++ 25-akpm/arch/i386/pci/irq.c Wed Aug 4 16:17:42 2004
@@ -1003,64 +1003,68 @@ int pirq_enable_irq(struct pci_dev *dev)
u8 pin;
extern int interrupt_line_quirk;
struct pci_dev *temp_dev;
+ char *msg;
+ msg = "";
+
+ /* VIA bridges use interrupt line for apic/pci steering across
+ the V-Link */
+ if (interrupt_line_quirk)
+ pci_write_config_byte(dev, PCI_INTERRUPT_LINE, dev->irq & 15);
pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
- if (pin && !pcibios_lookup_irq(dev, 1) && !dev->irq) {
- char *msg;
- msg = "";
- if (io_apic_assign_pci_irqs) {
- int irq;
- if (pin) {
- pin--; /* interrupt pins are numbered starting from 1 */
- irq = IO_APIC_get_PCI_irq_vector(dev->bus->number, PCI_SLOT(dev->devfn), pin);
- /*
- * Busses behind bridges are typically not listed in the MP-table.
- * In this case we have to look up the IRQ based on the parent bus,
- * parent slot, and pin number. The SMP code detects such bridged
- * busses itself so we should get into this branch reliably.
- */
- temp_dev = dev;
- while (irq < 0 && dev->bus->parent) { /* go back to the bridge */
- struct pci_dev * bridge = dev->bus->self;
-
- pin = (pin + PCI_SLOT(dev->devfn)) % 4;
- irq = IO_APIC_get_PCI_irq_vector(bridge->bus->number,
- PCI_SLOT(bridge->devfn), pin);
- if (irq >= 0)
- printk(KERN_WARNING "PCI: using PPB(B%d,I%d,P%d) to get irq %d\n",
- bridge->bus->number, PCI_SLOT(bridge->devfn), pin, irq);
- dev = bridge;
- }
- dev = temp_dev;
- if (irq >= 0) {
+ /* No irq for devices that don't need them, like legacy IDE. */
+ if (!pin || (dev->class >> 8 == PCI_CLASS_STORAGE_IDE && !(dev->class & 0x5)))
+ return 0;
+
+ /* Try $PIR table first */
+ if (pcibios_lookup_irq(dev, 1) || dev->irq)
+ return 0;
+
+ /* Next, try MPS */
+ if (io_apic_assign_pci_irqs) {
+ int irq;
+
+ pin--; /* interrupt pins are numbered starting from 1 */
+ irq = IO_APIC_get_PCI_irq_vector(dev->bus->number, PCI_SLOT(dev->devfn), pin);
+ /*
+ * Busses behind bridges are typically not listed in the MP-table.
+ * In this case we have to look up the IRQ based on the parent bus,
+ * parent slot, and pin number. The SMP code detects such bridged
+ * busses itself so we should get into this branch reliably.
+ */
+ temp_dev = dev;
+ while (irq < 0 && dev->bus->parent) { /* go back to the bridge */
+ struct pci_dev * bridge = dev->bus->self;
+
+ pin = (pin + PCI_SLOT(dev->devfn)) % 4;
+ irq = IO_APIC_get_PCI_irq_vector(bridge->bus->number,
+ PCI_SLOT(bridge->devfn), pin);
+ if (irq >= 0)
+ printk(KERN_WARNING "PCI: using PPB(B%d,I%d,P%d) to get irq %d\n",
+ bridge->bus->number, PCI_SLOT(bridge->devfn), pin, irq);
+ dev = bridge;
+ }
+ dev = temp_dev;
+ if (irq >= 0) {
#ifdef CONFIG_PCI_MSI
- if (!platform_legacy_irq(irq))
- irq = IO_APIC_VECTOR(irq);
+ if (!platform_legacy_irq(irq))
+ irq = IO_APIC_VECTOR(irq);
#endif
- printk(KERN_INFO "PCI->APIC IRQ transform: (B%d,I%d,P%d) -> %d\n",
- dev->bus->number, PCI_SLOT(dev->devfn), pin, irq);
- dev->irq = irq;
- return 0;
- } else
- msg = " Probably buggy MP table.";
- }
- } else if (pci_probe & PCI_BIOS_IRQ_SCAN)
- msg = "";
- else
- msg = " Please try using pci=biosirq.";
-
- /* With IDE legacy devices the IRQ lookup failure is not a problem.. */
- if (dev->class >> 8 == PCI_CLASS_STORAGE_IDE && !(dev->class & 0x5))
+ printk(KERN_INFO "PCI->APIC IRQ transform: (B%d,I%d,P%d) -> %d\n",
+ dev->bus->number, PCI_SLOT(dev->devfn), pin, irq);
+ dev->irq = irq;
return 0;
-
- printk(KERN_WARNING "PCI: No IRQ known for interrupt pin %c of device %s.%s\n",
- 'A' + pin - 1, pci_name(dev), msg);
- }
- /* VIA bridges use interrupt line for apic/pci steering across
- the V-Link */
- else if (interrupt_line_quirk)
- pci_write_config_byte(dev, PCI_INTERRUPT_LINE, dev->irq & 15);
+ } else
+ msg = " Probably buggy MP table.";
+ } else if (pci_probe & PCI_BIOS_IRQ_SCAN)
+ msg = "";
+ else
+ msg = " Please try using pci=biosirq.";
+
+ printk(KERN_WARNING "PCI: No IRQ known for interrupt pin %c of device %s.%s\n",
+ 'A' + pin - 1, pci_name(dev), msg);
+
return 0;
}
_