Re: [PATCH] intel_pstate: set BYT MSR with wrmsrl_on_cpu()
From: Rafael J. Wysocki
Date: Thu May 14 2015 - 19:48:46 EST
On Tuesday, May 12, 2015 07:59:42 AM Joe Konno wrote:
> From: Joe Konno <joe.konno@xxxxxxxxx>
> 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.
> v2: better commit message, remove For: tag
> Fixes: 007bea098b86 ("intel_pstate: Add setting voltage value for
> baytrail P states.")
> Signed-off-by: Joe Konno <joe.konno@xxxxxxxxx>
> drivers/cpufreq/intel_pstate.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
> diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
> index 6414661ac1c4..c45d274a75c8 100644
> --- a/drivers/cpufreq/intel_pstate.c
> +++ b/drivers/cpufreq/intel_pstate.c
> @@ -535,7 +535,7 @@ static void byt_set_pstate(struct cpudata *cpudata, int pstate)
> val |= vid;
> - wrmsrl(MSR_IA32_PERF_CTL, val);
> + wrmsrl_on_cpu(cpudata->cpu, MSR_IA32_PERF_CTL, val);
> #define BYT_BCLK_FREQS 5
Queued up for 4.2, thanks!
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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