Date: Fri, 8 Dec 2017 15:41:00 +0000 From: Alexey Dokuchaev <danfe@FreeBSD.org> To: Jung-uk Kim <jkim@FreeBSD.org> Cc: cem@freebsd.org, svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers <src-committers@freebsd.org> Subject: Re: svn commit: r326383 - head/sys/x86/cpufreq Message-ID: <20171208154100.GA5624@FreeBSD.org> In-Reply-To: <db23e689-d338-bc95-63c3-ce066f42a525@FreeBSD.org> References: <201711300140.vAU1e7dC001292@repo.freebsd.org> <CAG6CVpVyooSG3rPG1GvqRZHT9Lyh48JBQb_tFf2-CzWmfW8JyQ@mail.gmail.com> <e412e02d-8b52-221f-1f3c-8c300b1b3067@FreeBSD.org> <CAG6CVpVtm%2BUUw1zxxGXEjKT8MqL8ZjqSaQh4=_0NJbFmcbQxVw@mail.gmail.com> <af56c6b4-d964-4a19-5647-3778eb0cc508@FreeBSD.org> <20171207100345.GA59559@FreeBSD.org> <db23e689-d338-bc95-63c3-ce066f42a525@FreeBSD.org>
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On Thu, Dec 07, 2017 at 01:26:48PM -0500, Jung-uk Kim wrote: > On 12/07/2017 05:03, Alexey Dokuchaev wrote: > > On Thu, Nov 30, 2017 at 03:08:49PM -0500, Jung-uk Kim wrote: > >> ... > >> Probably. However, I am just trying to fix my FX-8350 and A10-6800 and > >> I don't have Zen processors to verify the MSRs are actually working on > >> those CPUs. > > > > Ah, that's so lovely, thanks Jung-uk; I feel that our support for AMD > > fam. 15h CPUs is lacking. E.g. only four P-states are reported for my > > A8-5550M, while it supports boosted P-states per BKDG, and reading MSRs > > directly via `sysutils/amdmsrtweaker' reports eight of them (P0 .. P7), > > with three turbo P-states P0 P1 P2. > > You don't trust your BIOS? ;-) Well, I kind of do, with a grain of salt. BIOSes (or shall I say, their CPU support packages) are often poorly written or being too conservative, in order to simplify vendors' job making sure they work across all CPUs. I also like to undervolt them; I'm doing this now with my Pentium M 780 CPU via patched DSDT. I hope that I could do the same for A8-5550M, and with having more P-states than currently provided via stock DSDT for a more fine-grained control. > Unless SSDT is unavailable or broken, we should use ACPI tables first. I know that's correct and recommended procedure; in fact, under Ubuntu, available frequency steps are: 2.10 GHz, 1.90 GHz, 1.70 GHz, 1.40 GHz; also just four (with driver: acpi-cpufreq). I'd have to boot into Win7 to see if it's doing more than that. ./danfe
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