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intel_pstate: Set CPU number before accessing MSRs 

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>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
hifive-unleashed-5.1
Vincent Minet 2014-07-05 01:51:33 +02:00 committed by Rafael J. Wysocki
parent 41629a8233
commit 179e847167
1 changed files with 1 additions and 2 deletions
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3
drivers/cpufreq/intel_pstate.c
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@ -700,9 +700,8 @@ static int intel_pstate_init_cpu(unsigned int cpunum)
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;