From c2b84b30b8c8bbccf4d2e32f8a3a70ad09ba9ab8 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 30 Jan 2008 13:33:04 +0100 Subject: x86: sanity check APIC timer frequency Check the APIC timer calibration result for sanity. When the frequency is out of range, issue a warning and disable the local APIC timer. Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar --- arch/x86/kernel/apic_32.c | 13 +++++++++++++ arch/x86/kernel/apic_64.c | 12 ++++++++++++ 2 files changed, 25 insertions(+) (limited to 'arch') diff --git a/arch/x86/kernel/apic_32.c b/arch/x86/kernel/apic_32.c index cbcf72cde956..20d4dbc42e6e 100644 --- a/arch/x86/kernel/apic_32.c +++ b/arch/x86/kernel/apic_32.c @@ -470,6 +470,19 @@ void __init setup_boot_APIC_clock(void) local_apic_timer_verify_ok = 1; + /* + * Do a sanity check on the APIC calibration result + */ + if (calibration_result < (1000000 / HZ)) { + local_irq_enable(); + printk(KERN_WARNING + "APIC frequency too slow, disabling apic timer\n"); + /* No broadcast on UP ! */ + if (num_possible_cpus() > 1) + setup_APIC_timer(); + return; + } + /* We trust the pm timer based calibration */ if (!pm_referenced) { apic_printk(APIC_VERBOSE, "... verify APIC timer\n"); diff --git a/arch/x86/kernel/apic_64.c b/arch/x86/kernel/apic_64.c index d1a696673d9d..731b48660fc4 100644 --- a/arch/x86/kernel/apic_64.c +++ b/arch/x86/kernel/apic_64.c @@ -383,6 +383,18 @@ void __init setup_boot_APIC_clock(void) printk(KERN_INFO "Using local APIC timer interrupts.\n"); calibrate_APIC_clock(); + /* + * Do a sanity check on the APIC calibration result + */ + if (calibration_result < (1000000 / HZ)) { + printk(KERN_WARNING + "APIC frequency too slow, disabling apic timer\n"); + /* No broadcast on UP ! */ + if (num_possible_cpus() > 1) + setup_APIC_timer(); + return; + } + /* * If nmi_watchdog is set to IO_APIC, we need the * PIT/HPET going. Otherwise register lapic as a dummy -- cgit v1.2.2