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authorThomas Gleixner <tglx@linutronix.de>2008-01-30 13:33:04 +0100
committerIngo Molnar <mingo@elte.hu>2008-01-30 13:33:04 +0100
commitc2b84b30b8c8bbccf4d2e32f8a3a70ad09ba9ab8 (patch)
treedb749014619fdef88cf458daad810ddd06023fe7
parent387faedb1dee2e917811acd05902cc36142a4850 (diff)
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 <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--arch/x86/kernel/apic_32.c13
-rw-r--r--arch/x86/kernel/apic_64.c12
2 files changed, 25 insertions, 0 deletions
diff --git a/arch/x86/kernel/apic_32.c b/arch/x86/kernel/apic_32.c
index cbcf72cde95..20d4dbc42e6 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 d1a696673d9..731b48660fc 100644
--- a/arch/x86/kernel/apic_64.c
+++ b/arch/x86/kernel/apic_64.c
@@ -384,6 +384,18 @@ void __init setup_boot_APIC_clock(void)
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
* device.