diff options
| author | Andreas Herrmann <andreas.herrmann3@amd.com> | 2008-09-18 21:12:10 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2008-09-23 11:38:53 +0200 |
| commit | 09bfeea13cea843fb03eaa96b5d891fa0abdcc90 (patch) | |
| tree | 83777d26c3029d373d67f61f6d08884ae275cea3 /arch/x86/kernel/process.c | |
| parent | x86: prevent C-states hang on AMD C1E enabled machines (diff) | |
| download | linux-09bfeea13cea843fb03eaa96b5d891fa0abdcc90.tar.xz linux-09bfeea13cea843fb03eaa96b5d891fa0abdcc90.zip | |
x86: c1e_idle: don't mark TSC unstable if CPU has invariant TSC
Impact: Functional TSC is marked unstable on AMD family 0x10 and 0x11 CPUs.
This would be wrong because for those CPUs "invariant TSC" means:
"The TSC counts at the same rate in all P-states, all C states, S0,
or S1"
(See "Processor BIOS and Kernel Developer's Guides" for those CPUs.)
[ tglx: Changed C1E to AMD C1E in the printks to avoid confusion
with Intel C1E ]
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86/kernel/process.c')
| -rw-r--r-- | arch/x86/kernel/process.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index d8c2a299bfe5..876e91890777 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -270,8 +270,9 @@ static void c1e_idle(void) rdmsr(MSR_K8_INT_PENDING_MSG, lo, hi); if (lo & K8_INTP_C1E_ACTIVE_MASK) { c1e_detected = 1; - mark_tsc_unstable("TSC halt in C1E"); - printk(KERN_INFO "System has C1E enabled\n"); + if (!boot_cpu_has(X86_FEATURE_CONSTANT_TSC)) + mark_tsc_unstable("TSC halt in AMD C1E"); + printk(KERN_INFO "System has AMD C1E enabled\n"); set_cpu_cap(&boot_cpu_data, X86_FEATURE_AMDC1E); } } |