From a2ef3a50f19f64d350bdc0aa15c31ae4b8973f57 Mon Sep 17 00:00:00 2001 From: Andy Currid Date: Thu, 8 Jun 2006 00:43:39 -0700 Subject: [PATCH] Fix HPET operation on 64-bit NVIDIA platforms From: "Andy Currid" This patch fixes a kernel panic during boot that occurs on NVIDIA platforms that have HPET enabled. When HPET is enabled, the standard timer IRQ is routed to IOAPIC pin 2 and is advertised as such in the ACPI APIC table - but an earlier workaround in the kernel was ignoring this override. The fix is to honor timer IRQ overrides from ACPI when HPET is detected on an NVIDIA platform. Signed-off-by: Andy Currid Cc: "Brown, Len" Cc: "Yu, Luming" Cc: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86_64/kernel/io_apic.c | 30 +++++++++++++++++++++++++----- 1 file changed, 25 insertions(+), 5 deletions(-) diff --git a/arch/x86_64/kernel/io_apic.c b/arch/x86_64/kernel/io_apic.c index 0de3ea93883..9cc7031b715 100644 --- a/arch/x86_64/kernel/io_apic.c +++ b/arch/x86_64/kernel/io_apic.c @@ -271,6 +271,18 @@ __setup("enable_8254_timer", setup_enable_8254_timer); #include #include + +#ifdef CONFIG_ACPI + +static int nvidia_hpet_detected __initdata; + +static int __init nvidia_hpet_check(unsigned long phys, unsigned long size) +{ + nvidia_hpet_detected = 1; + return 0; +} +#endif + /* Temporary Hack. Nvidia and VIA boards currently only work with IO-APIC off. Check for an Nvidia or VIA PCI bridge and turn it off. Use pci direct infrastructure because this runs before the PCI subsystem. @@ -317,11 +329,19 @@ void __init check_ioapic(void) return; case PCI_VENDOR_ID_NVIDIA: #ifdef CONFIG_ACPI - /* All timer overrides on Nvidia - seem to be wrong. Skip them. */ - acpi_skip_timer_override = 1; - printk(KERN_INFO - "Nvidia board detected. Ignoring ACPI timer override.\n"); + /* + * All timer overrides on Nvidia are + * wrong unless HPET is enabled. + */ + nvidia_hpet_detected = 0; + acpi_table_parse(ACPI_HPET, + nvidia_hpet_check); + if (nvidia_hpet_detected == 0) { + acpi_skip_timer_override = 1; + printk(KERN_INFO "Nvidia board " + "detected. Ignoring ACPI " + "timer override.\n"); + } #endif /* RED-PEN skip them on mptables too? */ return; -- cgit v1.2.3-70-g09d2