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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4C423C19F2C for ; Tue, 2 Aug 2022 13:11:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236488AbiHBNLC (ORCPT ); Tue, 2 Aug 2022 09:11:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51356 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232503AbiHBNLA (ORCPT ); Tue, 2 Aug 2022 09:11:00 -0400 Received: from mx.socionext.com (mx.socionext.com [202.248.49.38]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id BC0752737; Tue, 2 Aug 2022 06:10:56 -0700 (PDT) Received: from unknown (HELO iyokan2-ex.css.socionext.com) ([172.31.9.54]) by mx.socionext.com with ESMTP; 02 Aug 2022 22:10:55 +0900 Received: from mail.mfilter.local (m-filter-1 [10.213.24.61]) by iyokan2-ex.css.socionext.com (Postfix) with ESMTP id 2284F20584CE; Tue, 2 Aug 2022 22:10:55 +0900 (JST) Received: from 172.31.9.51 (172.31.9.51) by m-FILTER with ESMTP; Tue, 2 Aug 2022 22:10:55 +0900 Received: from [10.212.181.253] (unknown [10.212.181.253]) by kinkan2.css.socionext.com (Postfix) with ESMTP id E6092B62A4; Tue, 2 Aug 2022 22:10:53 +0900 (JST) Subject: Re: [PATCH 9/9] ARM: dts: uniphier: Remove compatible "snps,dw-pcie-ep" from Pro5 pcie-ep node To: Krzysztof Kozlowski , Arnd Bergmann Cc: Rob Herring , Krzysztof Kozlowski , Masami Hiramatsu , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <1656894026-15707-1-git-send-email-hayashi.kunihiko@socionext.com> <1656894026-15707-10-git-send-email-hayashi.kunihiko@socionext.com> <64e3702b-f09b-5a2e-b6a5-4c8752fbad77@linaro.org> From: Kunihiko Hayashi Message-ID: <612989a2-c6c7-5f04-a3ba-2a82667d420b@socionext.com> Date: Tue, 2 Aug 2022 22:10:53 +0900 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <64e3702b-f09b-5a2e-b6a5-4c8752fbad77@linaro.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2022/08/02 17:33, Krzysztof Kozlowski wrote: > On 30/07/2022 13:58, Arnd Bergmann wrote: >> On Mon, Jul 4, 2022 at 2:20 AM Kunihiko Hayashi >> wrote: >>> >>> UniPhier PCIe endpoint controller doesn't use "snps,dw-pcie-ep" >>> compatible, >>> so this is no longer needed. Remove the compatible string from the >>> pcie-ep >>> node to fix the following warning. >>> >>> uniphier-pro5-epcore.dtb: pcie@66000000: compatible: >>> ['socionext,uniphier-pro5-pcie-ep', 'snps,dw-pcie-ep'] is too long >>> From schema: >>> Documentation/devicetree/bindings/pci/socionext,uniphier-pcie-ep.yaml >>> >> >> This sounds like a problem with the binding rather than the dt file. Is >> this not >> a designware pci endpoint? Should it be documented in that binding >> instead? In term of the binding, it seems that the current binding doesn't allow descriptions that list two compatibles. There is something wrong with the binding. > Depends. We had one or two similar cases, where we dropped the snps/dw > generic compatible, because device was actually quite different and > could not match against snps/dw compatible. IOW, if device bound/matched > via generic compatible it would be entirely non-operational. Logically I > think it is okay to drop the generic compatible. Different question is > any ABI break. In term of the controller, we can add dw general compatible if the more generic driver (pcie-designware-plat) works on the controller. However, the generic driver can't do the initialization what the controller needs, so we can add controller-specific compatible only. The commit bf2942a8b7c3 ("arm64: tegra: Fix Tegra194 PCIe EP compatible string") removes the generic compatible for the same reason. This patch suggests removing the generic compatible for the former reason, though, I might suggest it for the controller reason. Thank you, --- Best Regards Kunihiko Hayashi