From owner-freebsd-bugs@freebsd.org Thu Sep 12 23:38:54 2019 Return-Path: Delivered-To: freebsd-bugs@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id D7072DDEF6 for ; Thu, 12 Sep 2019 23:38:54 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mailman.nyi.freebsd.org (unknown [127.0.1.3]) by mx1.freebsd.org (Postfix) with ESMTP id 46TwFp5RyRz3Py6 for ; Thu, 12 Sep 2019 23:38:54 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: by mailman.nyi.freebsd.org (Postfix) id B9257DDEF2; Thu, 12 Sep 2019 23:38:54 +0000 (UTC) Delivered-To: bugs@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id B8E74DDEF1 for ; Thu, 12 Sep 2019 23:38:54 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 46TwFp4V5Gz3Py4 for ; Thu, 12 Sep 2019 23:38:54 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2610:1c1:1:606c::50:1d]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 7EEC7264D7 for ; Thu, 12 Sep 2019 23:38:54 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.5]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id x8CNcseq098200 for ; Thu, 12 Sep 2019 23:38:54 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id x8CNcst3098199 for bugs@FreeBSD.org; Thu, 12 Sep 2019 23:38:54 GMT (envelope-from bugzilla-noreply@freebsd.org) X-Authentication-Warning: kenobi.freebsd.org: www set sender to bugzilla-noreply@freebsd.org using -f From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 240475] [PATCH]: Add support for CPUID 0x16 in tsc_freq_cpuid() (TSC clock) Date: Thu, 12 Sep 2019 23:38:53 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: CURRENT X-Bugzilla-Keywords: patch X-Bugzilla-Severity: Affects Some People X-Bugzilla-Who: neel@neelc.org X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: bugs@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 12 Sep 2019 23:38:54 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D240475 --- Comment #7 from Neel Chauhan --- It's true that Linux does this (lines 660-661): crystal_khz =3D eax_base_mhz * 1000 * eax_denominator / ebx_numerator; But in the same function, Linux returns this (line 674): return crystal_khz * ebx_numerator / eax_denominator; So the numerator and denominator in crystal_khz effectively cancels out on CPUID 0x16. >From what I understand, Linux expects the value in kilohertz, so a multipli= er of 1000 works on Linux. I believe FreeBSD expects hertz, so a multiplier of 1000000 is needed. For unit conversion of megahertz to hertz, 1000 Hz =3D 1 KHz and 1000 KHz = =3D 1 MHz, so 1 MHz =3D 1000 KHz * 1000 Hz. Also, using the numerator and denominator wouldn't work (I've tried that, I= got a kernel panic). --=20 You are receiving this mail because: You are the assignee for the bug.=