x86: Fix bogus warning in apic_noop.apic_write()

apic_noop is used to provide dummy apic functions. It's installed
when the CPU has no APIC or when the APIC is disabled on the kernel
command line.

The apic_noop implementation of apic_write() warns when the CPU has
an APIC or when the APIC is not disabled.

That's bogus. The warning should only happen when the CPU has an
APIC _AND_ the APIC is not disabled. apic_noop.apic_read() has the
correct check.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: <stable@kernel.org> # in <= .32 this typo resides in native_apic_write_dummy()
LKML-Reference: <alpine.LFD.2.00.0912071255420.3089@localhost.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/kernel/apic/apic_noop.c b/arch/x86/kernel/apic/apic_noop.c
index d9acc3b..e31b9ff 100644 (file)
--- a/arch/x86/kernel/apic/apic_noop.c
+++ b/arch/x86/kernel/apic/apic_noop.c
@@ -127,7 +127,7 @@ static u32 noop_apic_read(u32 reg)
 
 static void noop_apic_write(u32 reg, u32 v)
 {
-       WARN_ON_ONCE((cpu_has_apic || !disable_apic));
+       WARN_ON_ONCE(cpu_has_apic && !disable_apic);
 }
 
 struct apic apic_noop = {