From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 427dJ04lPHzF3C9 for ; Mon, 10 Sep 2018 03:21:20 +1000 (AEST) Message-ID: <7427daf6570d519e6793eb96d2fbaa52714b0cd7.camel@kernel.crashing.org> 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() From: Benjamin Herrenschmidt To: Frank Rowand , Finn Thain Cc: Stan Johnson , Rob Herring , Chintan Pandya , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Date: Sun, 09 Sep 2018 19:04:25 +0200 In-Reply-To: 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> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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.