From owner-freebsd-bugs@freebsd.org Mon May 2 21:07:05 2016 Return-Path: Delivered-To: freebsd-bugs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id DF50BB2A3DA for ; Mon, 2 May 2016 21:07:05 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2001:1900:2254:206a::16:76]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id CF8BC1BAA for ; Mon, 2 May 2016 21:07:05 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from bugs.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id u42L75Ap049788 for ; Mon, 2 May 2016 21:07:05 GMT (envelope-from bugzilla-noreply@freebsd.org) From: bugzilla-noreply@freebsd.org To: freebsd-bugs@FreeBSD.org Subject: [Bug 209202] [PATCH] [powermac_thermal] In-Kernel PowerMac fan control does not effectively regulate some quad core models Date: Mon, 02 May 2016 21:07:05 +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: 11.0-CURRENT X-Bugzilla-Keywords: patch X-Bugzilla-Severity: Affects Some People X-Bugzilla-Who: gmbroome@vcu.edu X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: freebsd-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: 2.1.22 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 02 May 2016 21:07:06 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D209202 --- Comment #3 from gmbroome@vcu.edu --- (In reply to Mark Millard from comment #2) The history on my work with this is that I grabbed two of these systems on = the cheap from "the Bay." Both had the "revision 2" CPU assembly, and both worked fine w/ OS X, Linux, and FreeBSD. Six months on, one of the cooling pumps in a system died. The only replace= ment that I could get was a "revision 1" CPU assembly. After doing the replacem= ent, both OS X and Linux continued to work fine (albeit with the same reduced performance that you noted) but FreeBSD showed the precise behavior that you described in the mailing list posts. Through a series of CPU assembly swaps, and ordering a second r.1 purely for the testing, I'm reasonably certain that the r.1 CPU assembly is, itself, t= he culprit. Though I certainly understand the notion that installing known-defective hardware (why else would there have been a rev?) will cause problems, it makes sense to go ahead and accommodate this r.1 CPU assembly = in the driver as the r.1 CPU assembly is the far more common replacement part these days, and r.2 is getting very difficult to obtain, even if one has bottomless pockets. Based on my own testing, the provided patch allows the= r.1 assemblies to work, and has a negligible impact on r.2 assemblies. --=20 You are receiving this mail because: You are the assignee for the bug.=