From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg1-x544.google.com (mail-pg1-x544.google.com [IPv6:2607:f8b0:4864:20::544]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 427nzJ6ykCzF38J for ; Mon, 10 Sep 2018 09:52:28 +1000 (AEST) Received: by mail-pg1-x544.google.com with SMTP id s15-v6so9506924pgv.8 for ; Sun, 09 Sep 2018 16:52:28 -0700 (PDT) Subject: Re: v4.17 regression: PowerMac G3 won't boot, was Re: [PATCH v5 1/3] of: cache phandle nodes to reduce cost of of_find_node_by_phandle() To: Benjamin Herrenschmidt , Finn Thain Cc: Stan Johnson , Rob Herring , Chintan Pandya , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Frank Rowand References: <1520208889-3908-1-git-send-email-frowand.list@gmail.com> <1520208889-3908-2-git-send-email-frowand.list@gmail.com> <0ad5dbfd-08f3-b97d-34b9-70fc9a729921@gmail.com> <7427daf6570d519e6793eb96d2fbaa52714b0cd7.camel@kernel.crashing.org> From: Frank Rowand Message-ID: <3d806f12-dd6f-63d7-92e0-0a79904dc4c9@gmail.com> Date: Sun, 9 Sep 2018 16:52:24 -0700 MIME-Version: 1.0 In-Reply-To: <7427daf6570d519e6793eb96d2fbaa52714b0cd7.camel@kernel.crashing.org> Content-Type: text/plain; charset=utf-8 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 09/09/18 10:04, Benjamin Herrenschmidt wrote: > On Fri, 2018-08-31 at 14:58 +1000, Benjamin Herrenschmidt wrote: >> >>> A long shot, but something to consider, is that I failed to cover the >>> cases of dynamic devicetree updates (removing nodes that contain a >>> phandle) in ways other than overlays. Michael Ellerman has reported >>> such a problem for powerpc/mobility with of_detach_node(). A patch to >>> fix that is one of the tasks I need to complete. >> >> The only thing I can think of is booting via the BootX bootloader on >> those ancient macs results in a DT with no phandles. I didn't see an >> obvious reason why that would cause that patch to break though. > > Guys, we still don't have a fix for this one on its way upstream... > > My test patch just creates phandle properties for all nodes, that was > not intended as a fix, more a way to check if the problem was related > to the lack of phandles. > > I don't actually know why the new code causes things to fail when > phandles are absent. This needs to be looked at. > > I'm travelling at the moment and generally caught up with other things, > I haven't had a chance to dig, so just a heads up. I don't intend to > submit my patch since it's just a band aid. We need to figure out what > the actual problem is. > > Cheers, > Ben. Thanks for chasing after this, and the current heads up. I agree that we need to understand what is going on and do a real fix. -Frank