diff options
Diffstat (limited to 'src/cpu/intel/haswell/haswell_init.c')
| -rw-r--r-- | src/cpu/intel/haswell/haswell_init.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/src/cpu/intel/haswell/haswell_init.c b/src/cpu/intel/haswell/haswell_init.c index 0e48876d10..9881bb880f 100644 --- a/src/cpu/intel/haswell/haswell_init.c +++ b/src/cpu/intel/haswell/haswell_init.c @@ -431,7 +431,9 @@ void set_power_limits(u8 power_limit_1_time) static void configure_c_states(void) { - msr_t msr; + msr_t msr = rdmsr(MSR_PLATFORM_INFO); + + const bool timed_mwait_capable = !!(msr.hi & TIMED_MWAIT_SUPPORTED); msr = rdmsr(MSR_PKG_CST_CONFIG_CONTROL); msr.lo |= (1 << 30); // Package c-state Undemotion Enable @@ -441,6 +443,10 @@ static void configure_c_states(void) msr.lo |= (1 << 26); // C1 Auto Demotion Enable msr.lo |= (1 << 25); // C3 Auto Demotion Enable msr.lo &= ~(1 << 10); // Disable IO MWAIT redirection + + if (timed_mwait_capable) + msr.lo |= (1 << 31); // Timed MWAIT Enable + /* The deepest package c-state defaults to factory-configured value. */ wrmsr(MSR_PKG_CST_CONFIG_CONTROL, msr); |