From a8d6829044901a67732904be5f1eacdf8539604f Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 22 Sep 2008 19:02:25 +0200 Subject: x86: prevent C-states hang on AMD C1E enabled machines Impact: System hang when AMD C1E machines switch into C2/C3 AMD C1E enabled systems do not work with normal ACPI C-states even if the BIOS is advertising them. Limit the C-states to C1 for the ACPI processor idle code. Signed-off-by: Thomas Gleixner --- include/asm-x86/acpi.h | 2 ++ include/asm-x86/cpufeature.h | 1 + 2 files changed, 3 insertions(+) (limited to 'include') diff --git a/include/asm-x86/acpi.h b/include/asm-x86/acpi.h index 635d764dc13e..35d1743b57ac 100644 --- a/include/asm-x86/acpi.h +++ b/include/asm-x86/acpi.h @@ -140,6 +140,8 @@ static inline unsigned int acpi_processor_cstate_check(unsigned int max_cstate) boot_cpu_data.x86_model <= 0x05 && boot_cpu_data.x86_mask < 0x0A) return 1; + else if (boot_cpu_has(X86_FEATURE_AMDC1E)) + return 1; else return max_cstate; } diff --git a/include/asm-x86/cpufeature.h b/include/asm-x86/cpufeature.h index 9489283a4bcf..cfcfb0a806ba 100644 --- a/include/asm-x86/cpufeature.h +++ b/include/asm-x86/cpufeature.h @@ -81,6 +81,7 @@ #define X86_FEATURE_LFENCE_RDTSC (3*32+18) /* Lfence synchronizes RDTSC */ #define X86_FEATURE_11AP (3*32+19) /* Bad local APIC aka 11AP */ #define X86_FEATURE_NOPL (3*32+20) /* The NOPL (0F 1F) instructions */ +#define X86_FEATURE_AMDC1E (3*32+21) /* AMD C1E detected */ /* Intel-defined CPU features, CPUID level 0x00000001 (ecx), word 4 */ #define X86_FEATURE_XMM3 (4*32+ 0) /* Streaming SIMD Extensions-3 */ -- cgit v1.2.3