Apologies. Patch now -p1-able.
[Apologies yet again, now includes description]
I'd submitted a patch earlier for this file, fixing a warning. When I looked at it further, I noticed it can output an incorrect warning message under certain circumstances. I've confirmed that this can and does happen in the wild:
PCI: Enabling device 0000:00:0a.0 (0000 -> 0001)
PCI: No IRQ known for interrupt pin @ of device 0000:00:0a.0. Probably buggy MP table.
It should read "No IRQ known for interrupt pin A", but the 'pin' variable has already been decremented (from 1 to 0), so the line:
printk(KERN_WARNING "PCI: No IRQ known for interrupt pin %c of device %s.%s\n", 'A' + pin - 1, dev->slot_name, msg);
causes "pin @" to be output, because 'A' + 0 - 1 == '@'.
This patch also fixes the original warning:
pci-irq.c: In function `pcibios_enable_irq': pci-irq.c:1128: warning: 'msg' might be used uninitialized in this function
Thanks,
Mark Haigh [EMAIL PROTECTED]
Signed-off-by: Mark F. Haigh <[EMAIL PROTECTED]>
--- linux-2.4.29-bk8/arch/i386/kernel/pci-irq.c.orig 2005-02-07 19:55:23.000000000 -0800 +++ linux-2.4.29-bk8/arch/i386/kernel/pci-irq.c 2005-02-07 20:13:38.000000000 -0800 @@ -1127,6 +1127,8 @@ if (pin && !pcibios_lookup_irq(dev, 1) && !dev->irq) { char *msg; + pin--; /* interrupt pins are numbered starting from 1 */ + /* With IDE legacy devices the IRQ lookup failure is not a problem.. */ if (dev->class >> 8 == PCI_CLASS_STORAGE_IDE && !(dev->class & 0x5)) return; @@ -1134,42 +1136,39 @@ 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; + 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) { - 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; - } else - msg = " Probably buggy MP table."; + 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) { + 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; + } 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, dev->slot_name, msg); + 'A' + pin, dev->slot_name, msg); } /* VIA bridges use interrupt line for apic/pci steering across the V-Link */