From e1afc3f522ed088405fc8932110d338330db82bb Mon Sep 17 00:00:00 2001 From: "Natalie.Protasevich@unisys.com" Date: Fri, 29 Jul 2005 14:03:32 -0700 Subject: [PATCH] [PATCH] x86: avoid wasting IRQs patch update The patch addresses a problem with ACPI SCI interrupt entry, which gets re-used, and the IRQ is assigned to another unrelated device. The patch corrects the code such that SCI IRQ is skipped and duplicate entry is avoided. Second issue came up with VIA chipset, the problem was caused by original patch assigning IRQs starting 16 and up. The VIA chipset uses 4-bit IRQ register for internal interrupt routing, and therefore cannot handle IRQ numbers assigned to its devices. The patch corrects this problem by allowing PCI IRQs below 16. Signed-off by: Natalie Protasevich Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/i386/kernel/mpparse.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/arch/i386/kernel/mpparse.c b/arch/i386/kernel/mpparse.c index af917f609c7d..ce838abb27d8 100644 --- a/arch/i386/kernel/mpparse.c +++ b/arch/i386/kernel/mpparse.c @@ -1116,7 +1116,15 @@ int mp_register_gsi (u32 gsi, int edge_level, int active_high_low) */ int irq = gsi; if (gsi < MAX_GSI_NUM) { - gsi = pci_irq++; + if (gsi > 15) + gsi = pci_irq++; +#ifdef CONFIG_ACPI_BUS + /* + * Don't assign IRQ used by ACPI SCI + */ + if (gsi == acpi_fadt.sci_int) + gsi = pci_irq++; +#endif gsi_to_irq[irq] = gsi; } else { printk(KERN_ERR "GSI %u is too high\n", gsi);