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| author | Takashi Iwai <tiwai@suse.de> | 2011-08-08 14:30:29 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2011-08-08 14:30:29 +0200 |
| commit | 0a2d31b62dba9b5b92a38c67c9cc42630513662a (patch) | |
| tree | f755d74ec85248de645e10c45ed1a2ed467530f6 /arch/x86/kernel/cpu/intel.c | |
| parent | 8039290a91c5dc4414093c086987a5d7738fe2fd (diff) | |
| parent | df944f66784e6d4f2f50739263a4947885d8b6ae (diff) | |
Merge branch 'fix/kconfig' into for-linus
Diffstat (limited to 'arch/x86/kernel/cpu/intel.c')
| -rw-r--r-- | arch/x86/kernel/cpu/intel.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index 1edf5ba4fb2..ed6086eedf1 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -456,6 +456,24 @@ static void __cpuinit init_intel(struct cpuinfo_x86 *c) if (cpu_has(c, X86_FEATURE_VMX)) detect_vmx_virtcap(c); + + /* + * Initialize MSR_IA32_ENERGY_PERF_BIAS if BIOS did not. + * x86_energy_perf_policy(8) is available to change it at run-time + */ + if (cpu_has(c, X86_FEATURE_EPB)) { + u64 epb; + + rdmsrl(MSR_IA32_ENERGY_PERF_BIAS, epb); + if ((epb & 0xF) == ENERGY_PERF_BIAS_PERFORMANCE) { + printk_once(KERN_WARNING "ENERGY_PERF_BIAS:" + " Set to 'normal', was 'performance'\n" + "ENERGY_PERF_BIAS: View and update with" + " x86_energy_perf_policy(8)\n"); + epb = (epb & ~0xF) | ENERGY_PERF_BIAS_NORMAL; + wrmsrl(MSR_IA32_ENERGY_PERF_BIAS, epb); + } + } } #ifdef CONFIG_X86_32 |