Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C1034C4332F for ; Mon, 10 Jan 2022 16:18:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237236AbiAJQST (ORCPT ); Mon, 10 Jan 2022 11:18:19 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59652 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237046AbiAJQSS (ORCPT ); Mon, 10 Jan 2022 11:18:18 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 54866C06173F; Mon, 10 Jan 2022 08:18:18 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 62522B81661; Mon, 10 Jan 2022 16:18:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1E420C36AF6; Mon, 10 Jan 2022 16:18:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1641831495; bh=rS4V/WO3etbLxGRygeuWlcXQr4ydR1z6tfJWlu1EtTE=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=d2mnaon2KYPN/QbKt30EQ243zPBjMmAIJ8VcqXYrjJ6ReupubGADw+v86TvDBoDCU InpXP3k2Vj0uBubhUDqClgoiBbDd2SOcmUFC2Uy+xoMI48PpqcqIVAxv8JCIEBPpzf AINBzxbMd3Y0jj8IaOsP5aQHkVMOazB5H63MjE5Zv+gbmIovnfvd7flys5uGVZoWkc C7bNiXOFUMlIG6ZXHauoU4yiGlB6vPv8vAebmpwTB9dYmajQOXTma5eG4hHC4hOsNe QMHM8vqJfjV3qMiRUTRqT0A/XElQr+9BS+XumDIWdilDv7aA5t+xOTezWvRxsFbNAO syjdwTdIbx4Xw== Received: by mail-ed1-f51.google.com with SMTP id m4so14150904edb.10; Mon, 10 Jan 2022 08:18:15 -0800 (PST) X-Gm-Message-State: AOAM531OXlqqBDeOWvFmuQ95YvHPPmfbiKrpaknvnvQwHT1FloalveWW aqLLf9ZCIgH4py69USBD7IEzPYfL1IVQXrI4Sw== X-Google-Smtp-Source: ABdhPJxzI/V2iQ9Y/D5SfWoyQ05XpKPBwP6qYhOYyRpWpiYpvr4ivTJ/0gQCDjzplq09Hl8rg61Ix1TRefJ0/NcCXNM= X-Received: by 2002:aa7:ce88:: with SMTP id y8mr357803edv.303.1641831493386; Mon, 10 Jan 2022 08:18:13 -0800 (PST) MIME-Version: 1.0 References: <20220110104214.25321-1-yu.tu@amlogic.com> <20220110104214.25321-2-yu.tu@amlogic.com> In-Reply-To: <20220110104214.25321-2-yu.tu@amlogic.com> From: Rob Herring Date: Mon, 10 Jan 2022 10:18:02 -0600 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH V5 1/5] dt-bindings: serial: meson: Drop legacy compatible. To: Yu Tu Cc: "open list:SERIAL DRIVERS" , linux-arm-kernel , "open list:ARM/Amlogic Meson..." , "linux-kernel@vger.kernel.org" , devicetree@vger.kernel.org, Greg Kroah-Hartman , Jiri Slaby , Neil Armstrong , Kevin Hilman , Jerome Brunet , Martin Blumenstingl Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jan 10, 2022 at 4:42 AM Yu Tu wrote: > > Deprecated, don't use anymore because legacy amlogic,meson-gx-uart > compatible. Don't differentiate between GXBB, GXL and G12A which > have different revisions of the UART IP. So it's split into > GXBB,GXL and G12A. You are breaking compatibility. If your dts is updated to use the new compatible, then a kernel without the change will not work anymore. It worked before without understanding the changes you are making. It should continue to. A compatible value like this would accomplish what you want: "amlogic,meson-gxbb-uart", "amlogic,meson-gx-uart", "amlogic,meson-ao-uart" A new kernel will match on "amlogic,meson-gxbb-uart" or "amlogic,meson-gx-uart" depending if the dtb is updated or not. An old kernel will continue to match on "amlogic,meson-gx-uart". If you are going to go breaking things, the power domain distinction in the compatible is odd... Rob