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 F1F79C32772 for ; Thu, 18 Aug 2022 13:57:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245138AbiHRN5q (ORCPT ); Thu, 18 Aug 2022 09:57:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33332 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245356AbiHRN5h (ORCPT ); Thu, 18 Aug 2022 09:57:37 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CFE90B5A48; Thu, 18 Aug 2022 06:57:36 -0700 (PDT) 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 dfw.source.kernel.org (Postfix) with ESMTPS id 6C886616EA; Thu, 18 Aug 2022 13:57:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 43DD5C433D6; Thu, 18 Aug 2022 13:57:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1660831055; bh=qqw2ZRKAM/HopXMmPqWG8KqLHJLGqfDq1lckUaBBS8Q=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Cy10ULQIGxDyatCWqA/3oow8PAmwyVzNy7YkqEZxmZKow0w5Jle1X0Yjd0Xhd9yyh kT7GDu4HtPhWfvw+9RX2zDgtjPuHSUYWwUyu1nK3MnHITs/ge3k9sJYhjCmkBf4dCo J8J/HbpmfS4SMrgrNTzJHwgTCU6uAMA6501rT8hu03C7AFx74utljnrtVJ8w0viSX4 0k9ykb6DQ4h+FxBxCgEId1kTbFGG4mZtCQ2CyrWgBFpx9rluHCQSmIwKutI0Pj8okm +encPvqOmVeKMqdHXtfC+8ePZIEY3In5ET6OQHUDpS6nkczYafXSeWo3GRCW6Y9/EC LhVcicOuVd/CA== Date: Thu, 18 Aug 2022 21:57:27 +0800 From: Shawn Guo To: Krzysztof Kozlowski Cc: Wei Fang , davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org, s.hauer@pengutronix.de, netdev@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, kernel@pengutronix.de, festevam@gmail.com, linux-imx@nxp.com, peng.fan@nxp.com, ping.bai@nxp.com, sudeep.holla@arm.com, linux-arm-kernel@lists.infradead.org, aisheng.dong@nxp.com Subject: Re: [PATCH 1/3] dt-bings: net: fsl,fec: update compatible item Message-ID: <20220818135727.GG149610@dragon> References: <20220704101056.24821-1-wei.fang@nxp.com> <20220704101056.24821-2-wei.fang@nxp.com> <20220818013344.GE149610@dragon> <20220818092257.GF149610@dragon> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Thu, Aug 18, 2022 at 12:46:33PM +0300, Krzysztof Kozlowski wrote: > On 18/08/2022 12:22, Shawn Guo wrote: > > On Thu, Aug 18, 2022 at 10:51:02AM +0300, Krzysztof Kozlowski wrote: > >> On 18/08/2022 04:33, Shawn Guo wrote: > >>> On Mon, Jul 04, 2022 at 11:12:09AM +0200, Krzysztof Kozlowski wrote: > >>>>> diff --git a/Documentation/devicetree/bindings/net/fsl,fec.yaml b/Documentation/devicetree/bindings/net/fsl,fec.yaml > >>>>> index daa2f79a294f..6642c246951b 100644 > >>>>> --- a/Documentation/devicetree/bindings/net/fsl,fec.yaml > >>>>> +++ b/Documentation/devicetree/bindings/net/fsl,fec.yaml > >>>>> @@ -40,6 +40,10 @@ properties: > >>>>> - enum: > >>>>> - fsl,imx7d-fec > >>>>> - const: fsl,imx6sx-fec > >>>>> + - items: > >>>>> + - enum: > >>>>> + - fsl,imx8ulp-fec > >>>>> + - const: fsl,imx6ul-fec > >>>> > >>>> This is wrong. fsl,imx6ul-fec has to be followed by fsl,imx6q-fec. I > >>>> think someone made similar mistakes earlier so this is a mess. > >>> > >>> Hmm, not sure I follow this. Supposing we want to have the following > >>> compatible for i.MX8ULP FEC, why do we have to have "fsl,imx6q-fec" > >>> here? > >>> > >>> fec: ethernet@29950000 { > >>> compatible = "fsl,imx8ulp-fec", "fsl,imx6ul-fec"; > >>> ... > >>> }; > >> > >> Because a bit earlier this bindings is saying that fsl,imx6ul-fec must > >> be followed by fsl,imx6q-fec. > > > > The FEC driver OF match table suggests that fsl,imx6ul-fec and fsl,imx6q-fec > > are not really compatible. > > > > static const struct of_device_id fec_dt_ids[] = { > > { .compatible = "fsl,imx25-fec", .data = &fec_devtype[IMX25_FEC], }, > > { .compatible = "fsl,imx27-fec", .data = &fec_devtype[IMX27_FEC], }, > > { .compatible = "fsl,imx28-fec", .data = &fec_devtype[IMX28_FEC], }, > > { .compatible = "fsl,imx6q-fec", .data = &fec_devtype[IMX6Q_FEC], }, > > { .compatible = "fsl,mvf600-fec", .data = &fec_devtype[MVF600_FEC], }, > > { .compatible = "fsl,imx6sx-fec", .data = &fec_devtype[IMX6SX_FEC], }, > > { .compatible = "fsl,imx6ul-fec", .data = &fec_devtype[IMX6UL_FEC], }, > > I don't see here any incompatibility. Binding driver with different > driver data is not a proof of incompatible devices. To me, different driver data is a good sign of incompatibility. It mostly means that software needs to program the hardware block differently. > Additionally, the > binding describes the hardware, not the driver. > > > { .compatible = "fsl,imx8mq-fec", .data = &fec_devtype[IMX8MQ_FEC], }, > > { .compatible = "fsl,imx8qm-fec", .data = &fec_devtype[IMX8QM_FEC], }, > > { /* sentinel */ } > > }; > > MODULE_DEVICE_TABLE(of, fec_dt_ids); > > > > Should we fix the binding doc? > > Maybe, I don't know. The binding describes the hardware, so based on it > the devices are compatible. Changing this, except ABI impact, would be > possible with proper reason, but not based on Linux driver code. Well, if Linux driver code is written in the way that hardware requires, I guess that's just based on hardware characteristics. To me, having a device compatible to two devices that require different programming model is unnecessary and confusing. Shawn