Date: Thu, 15 Sep 2011 13:42:38 -0700 From: Xin LI <delphij@gmail.com> To: "K. Macy" <kmacy@freebsd.org> Cc: FreeBSD-Current <freebsd-current@freebsd.org>, Arnaud Lacombe <lacombar@gmail.com>, Andriy Gapon <avg@freebsd.org> Subject: Re: 9.0-BETA2 do not support SpeedStep on E5420 Message-ID: <CAGMYy3vyLpedbmnUaxFYvX6WLgimH2A=qVxcp29M1oEQiogRvQ@mail.gmail.com> In-Reply-To: <CAHM0Q_PgPKi2R-wVkNi1HeNbU5KGf7H_LcUZPni6Je7=iWo8eQ@mail.gmail.com> References: <CACqU3MWNgq4RkBu7-eUON20CWdfO38KbM-8hR0AnFV-mn_=-7A@mail.gmail.com> <4E72505B.30700@FreeBSD.org> <CAHM0Q_PgPKi2R-wVkNi1HeNbU5KGf7H_LcUZPni6Je7=iWo8eQ@mail.gmail.com>
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On Thu, Sep 15, 2011 at 12:32 PM, K. Macy <kmacy@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 Developers
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@delphij.net> https://www.delphij.net/
FreeBSD - The Power to Serve! Live free or die
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