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=-5.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 E68FEC433E0 for ; Fri, 29 Jan 2021 08:30:51 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7671764E10 for ; Fri, 29 Jan 2021 08:30:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7671764E10 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=hisilicon.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:References:Subject:To:MIME-Version:From: Date:Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=IVNC7JLSGLS6sGy8E3RNmoZgSCMvbnzjll+PsJF0S1o=; b=Qglb2lmRAM2VHbMXnU0LfYqJu Pv+G87RDm4xhUorupLxTxxciKU7EsPYZR8Dmv1bCvTTN+8XWAozSHPTwtGr3ngMPBS1feSTzPhQ40 y8ecl5+ZfaR8MpkLsm5hno/m7dmpCE8N2meZvJmOH7+RpXPkvncXxFvKHn6JyH/6ZtqZsFU3W9xha bhJKWNPO6d+RshlrqYr9dCSNbYoDVGxh9ADbUAwqvUf1HBbjEAwu0tiV7N6ZTImmMQL+OpGBMDkjS Y/3O3oA9CB83KSqbFyJJyCnE9byws5puCuE9khpRc6PW76jyoBDjHhZwb420l+w4MC1GimslWTCkd 5jS0Y0XeA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l5PA0-0005M7-Cj; Fri, 29 Jan 2021 08:29:44 +0000 Received: from szxga04-in.huawei.com ([45.249.212.190]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1l5P9v-0005FG-K9 for linux-arm-kernel@lists.infradead.org; Fri, 29 Jan 2021 08:29:43 +0000 Received: from DGGEMS405-HUB.china.huawei.com (unknown [172.30.72.60]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4DRr6N6gTDz1606p; Fri, 29 Jan 2021 16:26:52 +0800 (CST) Received: from [10.40.166.221] (10.40.166.221) by DGGEMS405-HUB.china.huawei.com (10.3.19.205) with Microsoft SMTP Server id 14.3.498.0; Fri, 29 Jan 2021 16:27:57 +0800 Message-ID: <6013C70E.7050100@hisilicon.com> Date: Fri, 29 Jan 2021 16:27:58 +0800 From: Wei Xu User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 To: Arnd Bergmann Subject: Re: [PATCH v3 2/4] arm64: dts: correct vendor prefix hisi to hisilicon References: <20201208124641.1787-1-thunder.leizhen@huawei.com> <20201208124641.1787-3-thunder.leizhen@huawei.com> <6010B6DE.4060202@hisilicon.com> <60135EBA.5040803@hisilicon.com> <60136AFF.5080204@hisilicon.com> In-Reply-To: X-Originating-IP: [10.40.166.221] X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210129_032942_172477_1E5C3269 X-CRM114-Status: GOOD ( 16.21 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: devicetree , Mauro Carvalho Chehab , Chen Feng , Manivannan Sadhasivam , linux-kernel , Rob Herring , Philipp Zabel , Zhen Lei , Zhangfei Gao , linux-arm-kernel Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Arnd, On 2021/1/29 16:21, Arnd Bergmann wrote: > On Fri, Jan 29, 2021 at 2:57 AM Wei Xu wrote: >> On 2021/1/29 9:02, Wei Xu wrote: >>> On 2021/1/28 22:08, Arnd Bergmann wrote: >>>> 2. Updating the dtb while running an older kernel is now broken since >>>> the driver can no longer read the property. This is less critical, but >>>> it does seem easy enough to work around here by leaving both >>>> properties in place. >>> >>> Yes, it is. >>> But if leaving both in place, the dtbs_check will report following warning again: >>> 'hisi,rst-syscon' does not match any of the regexes >>> >>> That is why leizhen changed the dtb. >>> Do you think it is OK to assume no one will use the new dtb with an older kernel? >>> >>>> >>>> 3. Bisecting through the git history across an incompatible change >>>> means you can run into broken commits. We try hard to avoid that >>>> if we are aware of a problem in advance. In this case it could be >>>> avoided by only merging the incompatible DT change in a following >>>> merge window after the driver change, or (better) by making it >>>> a backward-compatible change the same way as addressing 2. >>> >>> Yes, agreed. >>> And The DT change pull request is sent after the driver has been merged into v5.11-rc1. >> >> I can drop this patch and revert what I have changed in Mauro's following patch: >> "arm64: dts: hisilicon: hi3670.dtsi: add iomcu_rst" >> >> Then resend the pull request. And pick up this patch after the next merge window. >> Do you think is it OK? > > Let's start with the updated pull request without this patch so I can merge > the other changes you sent. Got it. Thanks! > > I'm still not convinced it helps to drop the property rather than having > both. I think it should be possible to list the old property name in the > binding as 'deprecated' and keep it in the .dts for backwards compatibility > but leave it out in future dts files. Maybe move it into the board .dts file(s) > and make the .dtsi file have only the new property. Thanks! I will check with Lei Zhen to see which is possible. Best Regards, Wei > > Arnd > . > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel