From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Williams Subject: Re: linux-next: build failure after merge of the nvdimm tree Date: Mon, 9 Apr 2018 10:11:22 -0700 Message-ID: References: <20180409131619.0bc5fb45@canb.auug.org.au> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Oliver Cc: Stephen Rothwell , Linux-Next Mailing List , Linux Kernel Mailing List , Device Tree , Rob Herring List-Id: devicetree@vger.kernel.org On Mon, Apr 9, 2018 at 12:34 AM, Oliver wrote: > On Mon, Apr 9, 2018 at 1:38 PM, Oliver wrote: >> On Mon, Apr 9, 2018 at 1:16 PM, Stephen Rothwell wrote: >>> Hi Dan, >>> >>> After merging the nvdimm tree, today's linux-next build (x86_64 >>> allmodconfig) failed like this: >>> >>> ERROR: "of_node_to_nid" [drivers/nvdimm/of_pmem.ko] undefined! >>> >>> Caused by commit >>> >>> 717197608952 ("libnvdimm: Add device-tree based driver") >>> >>> X86 seems to not have a version of of_node_to_nid() even though CONFIG_OF >>> and CONFIG_NUMA are both 'y' in this build. >> >> It's a side effect of a driver selecting CONFIG_OF accidently. There's >> a patch to fix this in the drm-misc-next tree: >> >> https://lkml.org/lkml/2018/4/3/17 >> >>> I have used the nvdimm tree from next-20180406 for today. >> >> That works too. > > Hmm, on closer inspection this is actually a bug in the of driver. The > patch above fixes the specific problem that we hit on ia64 due to > CONFIG_OF being selected by accident, but the underlying issue will > affect any platform that doesn't provide an implementation of > of_node_to_nid(). > > The fundamental problem is that the various actual implementations of > of_node_to_nid (ppc, sparc and the generic one in of_numa.c) export > the symbol. While the fallback implementation does not because it is > defined as a weak symbol. As a result we'll get this build failure iff > there's a call to of_node_to_nid() in a module. > > The one-line fix is just to delete the call to of_node_to_nid() in > of_pmem.c. I have a patch that adds a Kconfig options and removes the > weak symbol games. That needs Acks from the ppc, sparc and DT > maintainers though so it'll take longer to organise. How about just marking OF_PMEM as bool for the time being until all of these other reworks land upstream?