diff options
Diffstat (limited to 'src/cpu')
| -rw-r--r-- | src/cpu/intel/haswell/haswell_init.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/src/cpu/intel/haswell/haswell_init.c b/src/cpu/intel/haswell/haswell_init.c index 01d151ee06..9984c55d95 100644 --- a/src/cpu/intel/haswell/haswell_init.c +++ b/src/cpu/intel/haswell/haswell_init.c @@ -404,6 +404,12 @@ static void set_max_ratio(void) static void set_energy_perf_bias(u8 policy) { msr_t msr; + int ecx; + + /* Determine if energy efficient policy is supported. */ + ecx = cpuid_ecx(0x6); + if (!(ecx & (1 << 3))) + return; /* Energy Policy is bits 3:0 */ msr = rdmsr(IA32_ENERGY_PERFORMANCE_BIAS); |