From owner-freebsd-bugs@freebsd.org Thu Sep 12 17:42:00 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 1D14FD51BE for ; Thu, 12 Sep 2019 17:42:00 +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 46TmL000VVz4X85 for ; Thu, 12 Sep 2019 17:42:00 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: by mailman.nyi.freebsd.org (Postfix) id F2356D51BD; Thu, 12 Sep 2019 17:41:59 +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 F0E63D51BC for ; Thu, 12 Sep 2019 17:41:59 +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 46TmKz6069z4X83 for ; Thu, 12 Sep 2019 17:41:59 +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 B127B224E2 for ; Thu, 12 Sep 2019 17:41:59 +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 x8CHfxgU035460 for ; Thu, 12 Sep 2019 17:41:59 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id x8CHfxUV035459 for bugs@FreeBSD.org; Thu, 12 Sep 2019 17:41:59 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 17:41:59 +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 17:42:00 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D240475 --- Comment #3 from Neel Chauhan --- This patch is based upon an existing Linux commit: https://github.com/torvalds/linux/commit/604dc9170f2435d27da5039a3efd757dce= adc684 In the commit message: Skylake, Kabylake and all variants of those two chipsets report a crystal frequency of zero, however we can calculate the crystal clock speed by condidering data from CPUID.0x16. This method correctly distinguishes between the two crystal clock frequencies present on different Skylake X variants that caused headaches before. As the calculations do not quite match the previously-hardcoded values in some cases (e.g. 23913043Hz instead of 24MHz), TSC refinement is enabled on all platforms where we had to calculate the crystal frequency in this way. This is also true on my system. I will post two verbose dmesgs: one without any patches, and one with this patch (which also has drm-kmod and Vladimir Kondratyev's iichid loaded). --=20 You are receiving this mail because: You are the assignee for the bug.=