From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ext-nj2ut-11.online-age.net (ext-nj2ut-11.online-age.net [64.14.54.241]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "ext-nj2ut.online-age.net", Issuer "Savvis Communications Root CA" (not verified)) by ozlabs.org (Postfix) with ESMTPS id 9379ADDF2E for ; Wed, 4 Feb 2009 02:50:32 +1100 (EST) Received: from int-nj2ut-3.online-age.net (int-nj2ut-3.online-age.net [3.159.237.72]) by ext-nj2ut-11.online-age.net (8.13.6/8.13.6/20051114-SVVS-TLS-DNSBL) with ESMTP id n13FoSW9031803 for ; Tue, 3 Feb 2009 10:50:28 -0500 Received: from cinmlip01.e2k.ad.ge.com (int-nj2ut-3.online-age.net [3.159.237.72]) by int-nj2ut-3.online-age.net (8.13.6/8.13.6/20050510-SVVS) with ESMTP id n13FoLqA011809 for ; Tue, 3 Feb 2009 10:50:27 -0500 Message-ID: <498867C0.2000607@gefanuc.com> Date: Tue, 03 Feb 2009 15:50:24 +0000 From: Martyn Welch MIME-Version: 1.0 To: Benjamin Herrenschmidt Subject: Re: Booting 2.6.29-rc3 on mpc8661d_hpcn failing References: <4982F311.4050507@gefanuc.com> <9B0CCADB-C891-42B2-BE94-0927B5715A00@kernel.crashing.org> <4986BEB9.3030606@gefanuc.com> <498718B6.3030307@gefanuc.com> <49871D3E.80809@gefanuc.com> <1233607753.18767.103.camel@pasglop> <49883719.9030300@gefanuc.com> In-Reply-To: <49883719.9030300@gefanuc.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Cc: linuxppc-dev list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Martyn Welch wrote: > Benjamin Herrenschmidt wrote: >>>>> commit 64b3d0e8122b422e879b23d42f9e0e8efbbf9744 >>>>> Author: Benjamin Herrenschmidt >>>>> >>>>> powerpc/mm: Rework usage of _PAGE_COHERENT/NO_CACHE/GUARDED >>>>> >>>>> I tried reverting it, but as I had kinda thought, that really >>>>> didn't help. >>>>> >>>>> I'm just recompiling to check that I didn't screw-up during the >>>>> bisection. >> >> Is this a chip that must not have M set ? Or something else ? You guys >> have to help if you CC me, I have about 0 idea what a MPC8661d is :-) >> > > Sorry, my fault. It's a Freescale SOC with two e600 cores. Beyond that, > I'm afraid I'm a little out of my depth. >> Also, does 4c456a67f501b8b15542c7c21c28812bf88f484b help ? > > I believe that to be included in 2.6.29-rc3 if my (rather rudimentary) > git skills haven't let me down? The problem persists in 2.6.29-rc3. > I've done a bit more investigation: The primary CPU is spinning in smp_generic_give_timebase() waiting for "!tbsync->ack". The secondary CPU has made it into smp_generic_take_timebase() and has apparently (according to some printk's I put in there) set "tbsync->ack=1". After that I don't get any printk's, I guess that the one I have put in the "!tbsync->handshake" while loop is making it to the print buffer, but with both processors spinning it's not getting to the serial console. At a guess, given that commit 64b3d0e8122b422e879b23d42f9e0e8efbbf9744 seems to be the point that it stopped working correctly, that "tbsync" is now somehow becoming cached? Martyn -- Martyn Welch MEng MPhil MIET (Principal Software Engineer) T:+44(0)1327322748 GE Fanuc Intelligent Platforms Ltd, |Registered in England and Wales Tove Valley Business Park, Towcester, |(3828642) at 100 Barbirolli Square, Northants, NN12 6PF, UK T:+44(0)1327359444 |Manchester,M2 3AB VAT:GB 729849476