From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [78.32.30.218]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E3D073009C1; Thu, 29 Jan 2026 14:36:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=78.32.30.218 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769697419; cv=none; b=qVTfS1GQRDOzNfOEH0zuEGJBfIJ9Q2GIKeIIcKB002vp94Y4j4Au2KcaoxXoj0Aj4r2n5smk9jBlF/d1TJ7He88ceSNRMRDobUIy+Wy9HuVWwcI7IwGHiZXBGWvEDYOP8ey+plLYLZDeyUJCRwqC/0Ub/FMiACvGJSXhwbrg8Y0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769697419; c=relaxed/simple; bh=yww0n1QNnrxlybVtSgCO21H3L4gn8OoO3+1JzIRppgM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Isk7dzi6TkbsWSRogH18k6m57M+tV/sv9sRC5I6H7t2l8PR6weik7e7ZmBa7quV5acKfGwrg5+9+X6ve35kXPNlL48DuTGbJKmulvJOpnO8CsU8PAgQtu3d65wgVw0qRAPy3uJY0kLpxOnUSth53X+zVEh7QlmzDkLRNuTJzhN4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=armlinux.org.uk; spf=none smtp.mailfrom=armlinux.org.uk; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b=IUnX78Xx; arc=none smtp.client-ip=78.32.30.218 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=armlinux.org.uk Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=armlinux.org.uk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="IUnX78Xx" 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=gdLx6MqvKMI7VkaiN5mQVnb2eVwGGL9NszyRmXRKFV0=; b=IUnX78XxTN3897xqwPd6BmA4/H EZehdxzJc8Fh5T/UIyymImNbkf0vAUqODyrY9JCzG8ckyviD4xiKe93el/EoD3p1JLof6a0DC3GNf MDMz6/TSocUiQyJUxzcbH9Xd2R6QBCL1sJWpQ6DzeMm3du9sH/8YX4h8VC04CU7DgWI3x87nqo0Fv +svJ8AlhFIV696xHGY3F35RC+v2S0PNnxW/If7wMVr310KDQjvREKy30qgwj74Ld1VIoUlzxxcb6U X8GtPYmrW8kuWScU4XpHe004klCUsff/h6SR7Iekv9OzSEGaTRSe3g9jRbp7X+ShCqfegy8iiMosG lkey1yOQ==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:37426) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.98.2) (envelope-from ) id 1vlT8a-000000000BS-2Vfn; Thu, 29 Jan 2026 14:36:48 +0000 Received: from linux by shell.armlinux.org.uk with local (Exim 4.98.2) (envelope-from ) id 1vlT8Y-0000000083Z-3wB7; Thu, 29 Jan 2026 14:36:46 +0000 Date: Thu, 29 Jan 2026 14:36:46 +0000 From: "Russell King (Oracle)" To: Vinod Koul Cc: Vincent Guittot , neil.armstrong@linaro.org, Simon Horman , krzk+dt@kernel.org, conor+dt@kernel.org, ciprianmarian.costea@oss.nxp.com, s32@nxp.com, p.zabel@pengutronix.de, ghennadi.procopciuc@nxp.com, Ionut.Vicovan@nxp.com, linux-phy@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, netdev@vger.kernel.org, Frank.li@nxp.com Subject: Re: [PATCH 2/4] phy: s32g: Add serdes subsystem phy Message-ID: References: <20260126092159.815968-1-vincent.guittot@linaro.org> <20260126092159.815968-3-vincent.guittot@linaro.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: Russell King (Oracle) On Thu, Jan 29, 2026 at 08:00:38PM +0530, Vinod Koul wrote: > On 29-01-26, 13:51, Russell King (Oracle) wrote: > > On Thu, Jan 29, 2026 at 02:36:01PM +0100, Vincent Guittot wrote: > > > On Thu, 29 Jan 2026 at 14:23, Russell King (Oracle) > > > wrote: > > > > > > > > On Thu, Jan 29, 2026 at 02:01:13PM +0100, Vincent Guittot wrote: > > > > > yes, the usual pattern is : > > > > > - phy_set_mode_ext() > > > > > - then phy_power_on() > > > > > but I can add an additional check > > > > > > > > Please read Documentation/driver-api/phy/phy.rst section "Order of API > > > > calls" which suggests phy_set_mode_ext() after phy_power_on(). > > > > > > Fair enough. > > > That being said, all pcie drivers that use phy_set_mode_ext(), call > > > it before phy_power_on() > > > > It looks like many ethernet drivers do the same, so I think maybe the > > generic PHY documentation is incorrect or misleading, or is expressing > > a preference that almost no one follows. Something for the generic PHY > > maintainers to look at and/or comment on. > > I would feel it makes sense to configure the mode first and then power > the phy up. As commented above yes it looks like apart from one tegra > driver rest seem to do it this way. > > Lets update the documentation Please also indicate in the documentation whether changing the submode of the serdes (particularly for ethernet) is permitted without doing a phy_power_down()..phy_power_up() dance around the phy_set_mode_ext() call. Thanks. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!