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Diffstat (limited to 'arch/x86_64/kernel/apic.c')
-rw-r--r--arch/x86_64/kernel/apic.c15
1 files changed, 13 insertions, 2 deletions
diff --git a/arch/x86_64/kernel/apic.c b/arch/x86_64/kernel/apic.c
index 396e125cb212..b2ead91df218 100644
--- a/arch/x86_64/kernel/apic.c
+++ b/arch/x86_64/kernel/apic.c
@@ -100,7 +100,7 @@ void clear_local_APIC(void)
maxlvt = get_maxlvt();
/*
- * Masking an LVT entry on a P6 can trigger a local APIC error
+ * Masking an LVT entry can trigger a local APIC error
* if the vector is zero. Mask LVTERR first to prevent this.
*/
if (maxlvt >= 3) {
@@ -851,7 +851,18 @@ void disable_APIC_timer(void)
unsigned long v;
v = apic_read(APIC_LVTT);
- apic_write(APIC_LVTT, v | APIC_LVT_MASKED);
+ /*
+ * When an illegal vector value (0-15) is written to an LVT
+ * entry and delivery mode is Fixed, the APIC may signal an
+ * illegal vector error, with out regard to whether the mask
+ * bit is set or whether an interrupt is actually seen on input.
+ *
+ * Boot sequence might call this function when the LVTT has
+ * '0' vector value. So make sure vector field is set to
+ * valid value.
+ */
+ v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
+ apic_write(APIC_LVTT, v);
}
}