Stefan Reinauer ([email protected]) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/2639
-gerrit commit 24b563dff1348294ceb7d3405229a02d0be253f3 Author: Aaron Durbin <[email protected]> Date: Tue Dec 11 17:15:13 2012 -0600 haswell: Properly Guard Engergy Policy by CPUID The IA32_ENERGY_PERFORMANCE_BIAS MSR can only be read or written to if the CPU supports it. The support is indicated by ECX[3] for cpuid(6). Without this guard, some Haswell parts would GP# fault in this routine. No more GP# while running on haswell CRBs. Change-Id: If41e1e133e5faebb3ed578cba60743ce7e1c196f Signed-off-by: Aaron Durbin <[email protected]> --- src/cpu/intel/haswell/haswell_init.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/src/cpu/intel/haswell/haswell_init.c b/src/cpu/intel/haswell/haswell_init.c index 01d151e..9984c55 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); -- coreboot mailing list: [email protected] http://www.coreboot.org/mailman/listinfo/coreboot
