From mboxrd@z Thu Jan 1 00:00:00 1970 From: Frank Rowand 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() Date: Sun, 9 Sep 2018 16:52:24 -0700 Message-ID: <3d806f12-dd6f-63d7-92e0-0a79904dc4c9@gmail.com> 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> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <7427daf6570d519e6793eb96d2fbaa52714b0cd7.camel@kernel.crashing.org> Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+glppe-linuxppc-embedded-2=m.gmane.org@lists.ozlabs.org Sender: "Linuxppc-dev" To: Benjamin Herrenschmidt , Finn Thain Cc: devicetree@vger.kernel.org, Stan Johnson , Frank Rowand , linux-kernel@vger.kernel.org, Rob Herring , Chintan Pandya , linuxppc-dev@lists.ozlabs.org List-Id: devicetree@vger.kernel.org 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