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Patch "intel_pstate: set BYT MSR with wrmsrl_on_cpu()" has been added to the 4.1-stable tree

PATCH [email protected] 1 participant 1 message Jul 8, 2015

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This is a note to let you know that I've just added the patch titled

intel_pstate: set BYT MSR with wrmsrl_on_cpu()

to the 4.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
intel_pstate-set-byt-msr-with-wrmsrl_on_cpu.patch
and it can be found in the queue-4.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From 0dd23f94251f49da99a6cbfb22418b2d757d77d6 Mon Sep 17 00:00:00 2001

From: Joe Konno <[email protected]>
Date: Tue, 12 May 2015 07:59:42 -0700
Subject: intel_pstate: set BYT MSR with wrmsrl_on_cpu()

From: Joe Konno <[email protected]>

commit 0dd23f94251f49da99a6cbfb22418b2d757d77d6 upstream.

Commit 007bea098b86 (intel_pstate: Add setting voltage value for baytrail P states.) introduced byt_set_pstate() with the assumption that it would always be run by the CPU whose MSR is to be written by it. It turns out, however, that is not always the case in practice, so modify byt_set_pstate() to enforce the MSR write done by it to always happen on the right CPU.

Fixes 007bea098b86 (intel_pstate: Add setting voltage value for baytrail P states.)
---
 drivers/cpufreq/intel_pstate.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/cpufreq/intel_pstate.c +1 -1
@@ -535,7 +535,7 @@ static void byt_set_pstate(struct cpudat
 
 	val |= vid;
 
-	wrmsrl(MSR_IA32_PERF_CTL, val);
+	wrmsrl_on_cpu(cpudata->cpu, MSR_IA32_PERF_CTL, val);
 }
 
 #define BYT_BCLK_FREQS 5

Patches currently in stable-queue which might be from [email protected] are

queue-4.1/intel_pstate-set-byt-msr-with-wrmsrl_on_cpu.patch