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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 523F9EE4996 for ; Sun, 20 Aug 2023 19:54:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=IJqxgik6FkvJgS7lhbckf2s6SncsFQTS9NRV+Xno4Dk=; b=w4UtUkpFrji4Df kzQlJCo/MsDcizlTG1dAMfnL8w6YXmnUfgTa0kGUwQXsotuYvvtixK+GNtGr9JRlvxZfcMu144KOF Oi8hEHdIyMLs/qfoRhj0EckugPbqCAK0hANE3my3KOQPcb7TGTPjfQYC6ZQwRcdMBDKbxmSl8LIkw ETLx8Gqj4O9fd3L0WaaMq3iKMIRelDAtXPKvONR/FDj0Uv+UWioTyqS9ahcxF+npe9Q3yWJGH958Y FkhAORr2DPx03ZiDab9oRU1D0Yap5otMFBS1grUqR6o8g7YWkOqVkwzH/uinXQLvYoj9plLj/78an oBeAGpXRrg/hKLXz0SIg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qXoV9-00CPY2-2U; Sun, 20 Aug 2023 19:54:19 +0000 Received: from [2001:4d48:ad52:32c8:5054:ff:fe00:142] (helo=pandora.armlinux.org.uk) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qXoV6-00CPOC-2A for linux-arm-kernel@lists.infradead.org; Sun, 20 Aug 2023 19:54:19 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=n6Nriy9y1QGK+aN6W7CXzj6VGKuJeaOqJSwIfNghFso=; b=ekRsQSuj716j10CXNiOb2CSmYq DRxAAxejcpIDPyiIUB5CsBHPqb/6wBnL1tarMzs95y8x0eCFqm4UKYlmvbTORt7HAEhKUdLz937bc w0SdeGRVuIpRldKcTQm5ml9s2EZtuHphBupIttx2tjbXyXRUv9ONZds/IUGSdMo8IlR/D/FiZH8XH WsLiGbh5a/nTlsE4AbaLXHqFfpJwc12ZkkztSnjKyuuTX62BLvKNz0oDpG1q36ayB9ZKEwgsya3x+ Xvx5o2YdzxJUZb1dbYmFyvDBZOjewxtVebysjmZLM78rEq1CSgSI+rMavH9lv9l7g60agO0anFlUc M7TMv9uQ==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:33380) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1qXoSe-0007mx-1P; Sun, 20 Aug 2023 20:51:44 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.94.2) (envelope-from ) id 1qXoSb-00041h-Fa; Sun, 20 Aug 2023 20:51:41 +0100 Date: Sun, 20 Aug 2023 20:51:41 +0100 From: "Russell King (Oracle)" To: Andrew Lunn Cc: Jisheng Zhang , "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Giuseppe Cavallaro , Alexandre Torgue , Jose Abreu , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH net-next v4 2/9] net: stmmac: xgmac: add more feature parsing from hw cap Message-ID: References: <20230816152926.4093-1-jszhang@kernel.org> <20230816152926.4093-3-jszhang@kernel.org> <9e55fd03-6b05-46de-874e-01d9cdbf4524@lunn.ch> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <9e55fd03-6b05-46de-874e-01d9cdbf4524@lunn.ch> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230820_125416_714591_274F91B6 X-CRM114-Status: GOOD ( 17.13 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 On Sun, Aug 20, 2023 at 09:15:06PM +0200, Andrew Lunn wrote: > On Wed, Aug 16, 2023 at 11:29:19PM +0800, Jisheng Zhang wrote: > > The XGMAC_HWFEAT_GMIISEL bit also indicates whether support 10/100Mbps > > or not. > > The commit message fails to explain the 'Why?' question. GMII does > normally imply 10/100/1000, so i would expect dma_cap->mbps_1000 also > implies 10/100/1000? So why also set dma_cap->mbps_10_100? > > Maybe a better change would be to modify: > > seq_printf(seq, "\t1000 Mbps: %s\n", > (priv->dma_cap.mbps_1000) ? "Y" : "N"); > > to actually say 10/100/1000 Mbps? It does not appear this is used for > anything other than debugfs? Indeed, it also looks to me like mbps_1000 and mbps_10_100 are only used to print things in the debugfs file, and do not have any effect on the driver. Moreover: drivers/net/ethernet/stmicro/stmmac/dwmac4.h:#define GMAC_HW_FEAT_GMIISEL BIT(1) drivers/net/ethernet/stmicro/stmmac/common.h:#define DMA_HW_FEAT_GMIISEL 0x00000002 /* 1000 Mbps Support */ drivers/net/ethernet/stmicro/stmmac/dwxgmac2.h:#define XGMAC_HWFEAT_GMIISEL BIT(1) Seems to be all the same bit, and: drivers/net/ethernet/stmicro/stmmac/dwmac4.h:#define GMAC_HW_FEAT_MIISEL BIT(0) drivers/net/ethernet/stmicro/stmmac/common.h:#define DMA_HW_FEAT_MIISEL 0x00000001 /* 10/100 Mbps Support */ So, if everyone defines the first few bits of the hw_cap identically, is there any point to decoding this separately in each driver? Couldn't the debugfs "show" function just parse the hw_cap directly? Wouldn't it make more sense to print MII / GMII rather than 10/100 and 1000 ? It does bring up one last question though: if the driver makes no use of these hw_cap bits, then is there any point in printing them in the debugfs file? -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last! _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel