From owner-freebsd-arm@FreeBSD.ORG Tue Oct 30 14:23:03 2012 Return-Path: Delivered-To: freebsd-arm@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id D9D6DECD; Tue, 30 Oct 2012 14:23:03 +0000 (UTC) (envelope-from freebsd@damnhippie.dyndns.org) Received: from duck.symmetricom.us (duck.symmetricom.us [206.168.13.214]) by mx1.freebsd.org (Postfix) with ESMTP id 7C2418FC14; Tue, 30 Oct 2012 14:23:03 +0000 (UTC) Received: from damnhippie.dyndns.org (daffy.symmetricom.us [206.168.13.218]) by duck.symmetricom.us (8.14.5/8.14.5) with ESMTP id q9UEN2Pm062530; Tue, 30 Oct 2012 08:23:02 -0600 (MDT) (envelope-from freebsd@damnhippie.dyndns.org) Received: from [172.22.42.240] (revolution.hippie.lan [172.22.42.240]) by damnhippie.dyndns.org (8.14.3/8.14.3) with ESMTP id q9UEMeZR005574; Tue, 30 Oct 2012 08:22:40 -0600 (MDT) (envelope-from freebsd@damnhippie.dyndns.org) Subject: Re: BeagleBone questions (was Re: Towards an ARM system-building script) From: Ian Lepore To: Alie Tan In-Reply-To: References: <2E208EEB-B2CF-4AC6-B420-03FB4CF08041@freebsd.org> <1351522908.1123.356.camel@revolution.hippie.lan> <1351550400.1123.364.camel@revolution.hippie.lan> Content-Type: text/plain; charset="us-ascii" Date: Tue, 30 Oct 2012 08:22:40 -0600 Message-ID: <1351606960.1120.21.camel@revolution.hippie.lan> Mime-Version: 1.0 X-Mailer: Evolution 2.32.1 FreeBSD GNOME Team Port Content-Transfer-Encoding: 7bit Cc: "freebsd-arm@freebsd.org" X-BeenThere: freebsd-arm@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Porting FreeBSD to the StrongARM Processor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 30 Oct 2012 14:23:04 -0000 On Tue, 2012-10-30 at 18:42 +0800, Alie Tan wrote: > On Tue, Oct 30, 2012 at 6:40 AM, Ian Lepore > wrote: > > > On Mon, 2012-10-29 at 09:14 -0700, Adrian Chadd wrote: > > > On 29 October 2012 08:08, Alie Tan wrote: > > > > I have tried angstrom, ArchLinux and FreBSD. Only FreeBSD makes the > > > > chip/board quite hot. > > > > > > > > Anyone have same experiece? > > > > > > Are we not halting the CPU during idle ticks on ARM? > > > > > > Does Linux have some extra power management code for ARM that we don't? > > > > I'm not sure all arm SoCs we support have the ability to do this well > > (or at all). I know for sure the atmel chips can do it, and we don't > > use that abillity. We're pretty poor on power management in general in > > the atmel world. I mean poor, like we turn on all on-chip devices early > > in kernel init and leave them that way, even the ones we don't have > > drivers for. A comment in the code labels that a "temporary hack" but > > it's been that way for 5 years. > > > > More directly on the OP's point, I wonder if the combo of the system not > > fully booting and too much heat imply that something has gone into a > > tight loop somewhere. > > > Is there any way to debug/detect this issue? > I cant see any heavy processes from 'top' > Well if the system is running well enough to use top, and it isn't showing any process or kernel thread using a ton of cpu, then I think that probably invalidates my theory. One of my arm eval boards has an LCD interface that I don't use, and a note with the system mentioned that there's a part on the board that will heat up if you don't connect a display; they recommend unsoldering it. The part is some sort of choke or coil (it's silkscreened as "L11"). On my board it gets warm, not really hot, so I haven't bothered to remove it. -- Ian