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authorSiddha, Suresh B <suresh.b.siddha@intel.com>2006-06-26 13:59:53 +0200
committerLinus Torvalds <torvalds@g5.osdl.org>2006-06-26 10:48:22 -0700
commit704fc59e1d056de80beaf30174bc8e0b1682efbb (patch)
tree0b6d3e62105d680b5c8deac2fa614de42293923a /arch/x86_64
parent03fdc2c277afdbd217eccd1ce0cfeff77ebd8b77 (diff)
[PATCH] x86_64: fix apic error on bootup
Appended patch fixes the "APIC error on CPUX: 00(40)" observed during bootup. From SDM Vol-3A "Valid Interrupt Vectors" section: "When an illegal vector value (0-15) is written to an LVT entry and the 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." Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/x86_64')
-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 396e125cb21..b2ead91df21 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);
}
}