| From 179e8471673ce0249cd4ecda796008f7757e5bad Mon Sep 17 00:00:00 2001 |
| From: Vincent Minet <vincent@vincent-minet.net> |
| Date: Sat, 5 Jul 2014 01:51:33 +0200 |
| Subject: intel_pstate: Set CPU number before accessing MSRs |
| |
| From: Vincent Minet <vincent@vincent-minet.net> |
| |
| commit 179e8471673ce0249cd4ecda796008f7757e5bad upstream. |
| |
| Ensure that cpu->cpu is set before writing MSR_IA32_PERF_CTL during CPU |
| initialization. Otherwise only cpu0 has its P-state set and all other |
| cores are left with their values unchanged. |
| |
| In most cases, this is not too serious because the P-states will be set |
| correctly when the timer function is run. But when the default governor |
| is set to performance, the per-CPU current_pstate stays the same forever |
| and no attempts are made to write the MSRs again. |
| |
| Signed-off-by: Vincent Minet <vincent@vincent-minet.net> |
| Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/cpufreq/intel_pstate.c | 3 +-- |
| 1 file changed, 1 insertion(+), 2 deletions(-) |
| |
| --- a/drivers/cpufreq/intel_pstate.c |
| +++ b/drivers/cpufreq/intel_pstate.c |
| @@ -709,9 +709,8 @@ static int intel_pstate_init_cpu(unsigne |
| |
| cpu = all_cpu_data[cpunum]; |
| |
| - intel_pstate_get_cpu_pstates(cpu); |
| - |
| cpu->cpu = cpunum; |
| + intel_pstate_get_cpu_pstates(cpu); |
| |
| init_timer_deferrable(&cpu->timer); |
| cpu->timer.function = intel_pstate_timer_func; |
