[3.11.y.z extended stable] Patch "intel_pstate: fix no_turbo" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    intel_pstate: fix no_turbo

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

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>From f4d45939cd736673b95bbf6f0f0cb51c5bfe78a5 Mon Sep 17 00:00:00 2001
From: Srinivas Pandruvada <srinivas.pandruvada at linux.intel.com>
Date: Tue, 1 Oct 2013 10:28:41 -0700
Subject: intel_pstate: fix no_turbo

commit 1ccf7a1cdafadd02e33e8f3d74370685a0600ec6 upstream.

When sysfs for no_turbo is set, then also some p states in turbo regions
are observed. This patch will set IDA Engage bit when no_turbo is set to
explicitly disengage turbo.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada at linux.intel.com>
Acked-by: Dirk Brandewie <dirk.j.brandewie at intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki at intel.com>
Cc: Joseph Salisbury <joseph.salisbury at canonical.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/cpufreq/intel_pstate.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index e8c3db8..f112f7d 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -394,7 +394,10 @@ static void intel_pstate_set_pstate(struct cpudata *cpu, int pstate)
 	trace_cpu_frequency(pstate * 100000, cpu->cpu);

 	cpu->pstate.current_pstate = pstate;
-	wrmsrl(MSR_IA32_PERF_CTL, pstate << 8);
+	if (limits.no_turbo)
+		wrmsrl(MSR_IA32_PERF_CTL, BIT(32) | (pstate << 8));
+	else
+		wrmsrl(MSR_IA32_PERF_CTL, pstate << 8);

 }

--
1.8.3.2