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authorAlexey Starikovskiy <aystarik@gmail.com>2007-11-26 20:42:19 +0100
committerIngo Molnar <mingo@elte.hu>2007-11-26 20:42:19 +0100
commitc1c306344669ca40255e36192b101060ffbb1271 (patch)
tree292c7936d91b8ed2febb3e2902de41d0e6c84bca /include/asm-x86
parentd4d25deca49ec2527a634557bf5a6cf449f85deb (diff)
ACPI: Set max_cstate to 1 for early Opterons.
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>
Diffstat (limited to 'include/asm-x86')
-rw-r--r--include/asm-x86/acpi.h27
1 files changed, 27 insertions, 0 deletions
diff --git a/include/asm-x86/acpi.h b/include/asm-x86/acpi.h
index 0693689d4146..f8a89793ac8c 100644
--- a/include/asm-x86/acpi.h
+++ b/include/asm-x86/acpi.h
@@ -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