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Commit 03a05ed1 authored by Zhao Yakui's avatar Zhao Yakui Committed by Len Brown
Browse files

ACPI: Use the ARB_DISABLE for the CPU which model id is less than 0x0f. 

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: default avatarZhao Yakui <yakui.zhao@intel.com>
Acked-by: default avatarPallipadi, Venkatesh <venkatesh.pallipadi@intel.com>
cc: stable@kernel.org
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent 22763c5c

arch/x86/kernel/acpi/cstate.c

+1 −1
Original line number Diff line number Diff line
@@ -48,7 +48,7 @@ void acpi_processor_power_init_bm_check(struct acpi_processor_flags *flags, 
	 * 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);