intel_pstate: Set CPU number before accessing MSRs
authorVincent Minet <vincent@vincent-minet.net>
Fri, 4 Jul 2014 23:51:33 +0000 (01:51 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 17 Jul 2014 23:21:05 +0000 (16:21 -0700)
commitbc5c48b656b5000536340c403b42ea52f5965ccf
treef2511704b7ddb9c518b6a1294cb137f78598e381
parent1c28f6e99733de8ee33296ad66ce698692208d8a
intel_pstate: Set CPU number before accessing MSRs

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