From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9C3BDC11F68 for ; Wed, 14 Jul 2021 12:55:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7621A60230 for ; Wed, 14 Jul 2021 12:55:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239378AbhGNM6C (ORCPT ); Wed, 14 Jul 2021 08:58:02 -0400 Received: from mail.baikalelectronics.com ([87.245.175.226]:47070 "EHLO mail.baikalelectronics.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231384AbhGNM6B (ORCPT ); Wed, 14 Jul 2021 08:58:01 -0400 X-Greylist: delayed 416 seconds by postgrey-1.27 at vger.kernel.org; Wed, 14 Jul 2021 08:58:00 EDT Date: Wed, 14 Jul 2021 15:48:07 +0300 From: Serge Semin To: John Stultz CC: Serge Semin , Felipe Balbi , Krzysztof Kozlowski , Florian Fainelli , Rob Herring , Greg Kroah-Hartman , Andy Gross , Bjorn Andersson , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , linux-arm-msm , Linux USB List , lkml , linux-arm-kernel , Amit Pundir Subject: Re: [PATCH 29/29] arm64: dts: qcom: Harmonize DWC USB3 DT nodes name Message-ID: <20210714124807.o22mottsrg3tv6nt@mobilestation> References: <20201020115959.2658-1-Sergey.Semin@baikalelectronics.ru> <20201020115959.2658-30-Sergey.Semin@baikalelectronics.ru> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: MAIL.baikal.int (192.168.51.25) To mail (192.168.51.25) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello John, On Tue, Jul 13, 2021 at 05:07:00PM -0700, John Stultz wrote: > On Tue, Oct 20, 2020 at 5:10 AM Serge Semin > wrote: > > > > In accordance with the DWC USB3 bindings the corresponding node > > name is suppose to comply with the Generic USB HCD DT schema, which > > requires the USB nodes to have the name acceptable by the regexp: > > "^usb(@.*)?" . Make sure the "snps,dwc3"-compatible nodes are correctly > > named. > > > > Signed-off-by: Serge Semin > > I know folks like to ignore this, but this patch breaks AOSP on db845c. :( Sorry to hear that. Alas there is no much can be done about it. DT-nodes name is a subject of DT-schema convention and as we've finally unified USB-controller nodes it shouldn't be reverted back. You can find the final USB-controller bindings in: Documentation/devicetree/bindings/usb/usb.yaml It strictly defines to have USB-nodes with names like "usb(@.*)". Reverting this patch will cause the DT-bindings check procedure failure. You can also find the naming convention defined in the latest DT spec: https://github.com/devicetree-org/devicetree-specification/releases/tag/v0.3 See also device-tree bindings requirements listed in the file: Documentation/devicetree/bindings/writing-bindings.rst It says: "DO use node names matching the class of the device. Many standard names are defined in the DT Spec. If there isn't one, consider adding it." > > In the exact same way an earlier patch broke HiKey960: > https://lore.kernel.org/lkml/CALAqxLWGujgR7p8Vb5S_RimRVYxwm5XF-c4NkKgMH-43wEBaWg@mail.gmail.com/ > > (which I still have to carry a revert for). > > I get that this change is useful so more dynamic userland can find > devices using consistent naming with future kernels (but doesn't the > dynamic userland have to handle the case for older kernels as well?) > But for userland that uses static configs, its painful as updating > userland to use the new node ids then causes older kernels to fail. > > I'm looking into how we might be able to probe and set the property > dynamically, but AOSP's init system is far more aligned to static > configs. > As Krzysztof said in https://lore.kernel.org/lkml/20201221210423.GA2504@kozik-lap/ and Bjorn noted in his response to your email, the only way to solve the problem is to fix the user-land app so one would be able to deal with both old and new DT-nodes name. Alternatively you can just replace the dts with older one, where the name still have the "dwc3"-prefix. -Sergey > This will probably be ignored again, but it would be nice if we could > have a release where DTS changes don't break userland for one of my > boards. As it feels like its been awhile. > > thanks > -john