linux-kernel - Re: [PATCH 2/2] x86/tsc: Add additional Intel CPU models to crystal

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Date:   Thu, 15 Sep 2016 13:48:00 -0400
From:   Prarit Bhargava <prarit@...hat.com>
To:     Peter Zijlstra <peterz@...radead.org>,
        "Brown, Len" <len.brown@...el.com>
CC:     "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>,
        "H. Peter Anvin" <hpa@...or.com>,
        "x86@...nel.org" <x86@...nel.org>,
        Rafael Aquini <aquini@...hat.com>,
        Andy Lutomirski <luto@...nel.org>,
        "lenb@...nel.org" <lenb@...nel.org>
Subject: Re: [PATCH 2/2] x86/tsc: Add additional Intel CPU models to crystal_khz
 whitelist



On 09/15/2016 01:43 PM, Peter Zijlstra wrote:
> On Thu, Sep 15, 2016 at 04:08:36PM +0000, Brown, Len wrote:
>>> +			crystal_khz = 24000;	/* 25.0 MHz */
>>
>> I guess I prefer no comment over an incorrect comment.
>>
> 
> From this I take it it should really have been 24 MHz and it could have
> joined the existing case. I assumed (ha!) that since it had a special
> separate case the comment was correct.

AFAICT, it should be 25000.  Len -- can you explicitly confirm that?  The
turbostat code contains (tools/power/x86/turbostat/turbostat.c:3312)

                                case 0x55:      /* SKX */
                                        crystal_hz = 25000000;  /* 25.0 MHz */


P.

>