[132/151] ACPI: Use the ARB_DISABLE for the CPU which model id is less than 0x0f.

[Greg KH]

2.6.32-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Zhao Yakui <yakui.zhao@xxxxxxxxx>

commit 03a05ed1152944000151d57b71000de287a1eb02 upstream.

Currently, ARB_DISABLE is a NOP on all of the recent Intel platforms.
For such platforms, reduce contention on c3_lock by skipping the fake
ARB_DISABLE.

The cpu model id on one laptop is 14. If we disable ARB_DISABLE on this box,
the box can't be booted correctly. But if we still enable ARB_DISABLE on this
box, the box can be booted correctly.

So we still use the ARB_DISABLE for the cpu which mode id is less than 0x0f.

http://bugzilla.kernel.org/show_bug.cgi?id=14700

Signed-off-by: Zhao Yakui <yakui.zhao@xxxxxxxxx>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@xxxxxxxxx>
Signed-off-by: Len Brown <len.brown@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 arch/x86/kernel/acpi/cstate.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/kernel/acpi/cstate.c
+++ b/arch/x86/kernel/acpi/cstate.c
@@ -48,7 +48,7 @@ void acpi_processor_power_init_bm_check(
 	 * P4, Core and beyond CPUs
 	 */
 	if (c->x86_vendor == X86_VENDOR_INTEL &&
-	    (c->x86 > 0xf || (c->x86 == 6 && c->x86_model >= 14)))
+	    (c->x86 > 0xf || (c->x86 == 6 && c->x86_model >= 0x0f)))
 			flags->bm_control = 0;
 }
 EXPORT_SYMBOL(acpi_processor_power_init_bm_check);


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