9.0-BETA2 do not support SpeedStep on E5420

[Xin LI]

On Thu, Sep 15, 2011 at 12:32 PM, K. Macy <kmacy at freebsd.org> wrote:
[...]
> sys/x86/cpufreq/est.c:1008
>
>        /* Attempt to enable SpeedStep if not currently enabled. */
>        msr = rdmsr(MSR_MISC_ENABLE);
>        if ((msr & MSR_SS_ENABLE) == 0) {
>                wrmsr(MSR_MISC_ENABLE, msr | MSR_SS_ENABLE);
>                if (bootverbose)
>                        device_printf(dev, "enabling SpeedStep\n");
>
>                /* Check if the enable failed. */
>                msr = rdmsr(MSR_MISC_ENABLE);
>                if ((msr & MSR_SS_ENABLE) == 0) {
>                        device_printf(dev, "failed to enable SpeedStep\n");
>                        return (ENXIO);

Looking at the Intel® 64 and IA-32 Architectures Software Developer’s
Manual (section 14.1), I think the code here is right?

(I'd expect Linux do the same since the code are mostly the same there).

Cheers,
-- 
Xin LI <delphij at delphij.net> https://www.delphij.net/
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