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ACPI: Set max_cstate to 1 for early Opterons.

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AMD Opteron processors before CG revision don't like C-states > 1.

This solves the long standing bugzilla #5303 and probably some more
on affected machines:

  http://bugzilla.kernel.org/show_bug.cgi?id=5303

[ tglx@linutronix.de: reworked the patch so it does not wreck ia64 ]

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Alexey Starikovskiy
2007-11-26 20:42:19 +01:00
committed by Ingo Molnar
parent d4d25deca4
commit c1c3063446
3 changed files with 29 additions and 0 deletions
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27
include/asm-x86/acpi.h
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@@ -1,5 +1,32 @@
#ifndef _ASM_X86_ACPI_H
#define _ASM_X86_ACPI_H
#ifdef CONFIG_X86_32
# include "acpi_32.h"
#else
# include "acpi_64.h"
#endif
#include <asm/processor.h>
/*
* Check if the CPU can handle C2 and deeper
*/
static inline unsigned int acpi_processor_cstate_check(unsigned int max_cstate)
{
/*
* Early models (<=5) of AMD Opterons are not supposed to go into
* C2 state.
*
* Steppings 0x0A and later are good
*/
if (boot_cpu_data.x86 == 0x0F &&
boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
boot_cpu_data.x86_model <= 0x05 &&
boot_cpu_data.x86_mask < 0x0A)
return 1;
else
return max_cstate;
}
#endif