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 X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CF7E6C433DF for ; Tue, 23 Jun 2020 09:56:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A79C120724 for ; Tue, 23 Jun 2020 09:56:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="zgSWOu4N" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732178AbgFWJ4w (ORCPT ); Tue, 23 Jun 2020 05:56:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40290 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731947AbgFWJ4v (ORCPT ); Tue, 23 Jun 2020 05:56:51 -0400 Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [IPv6:2001:4d48:ad52:32c8:5054:ff:fe00:142]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A9A97C061573; Tue, 23 Jun 2020 02:56:51 -0700 (PDT) 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-Transfer-Encoding:Content-Type: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-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=fVbOM75xv50lUOUamFW/PCZWwW1H+bw+wE9vcoAR+6c=; b=zgSWOu4NiJmUNVTnO3A59o0wG LnICkTXubnN/Yj6EczhmPZGplS3lQuoufgG+aHHXAPqPHOHndEFVYwHCeU3yoHXFwTKA2mW09/z1u ApMlIuqhIyf5Pubd/Ei2XrjJ269MP+GMf4pJhEyAIHDrqlABTFhN2MhU9+XK5w9rXFEau5Im8nQkQ +wkNyBSTQ1FEMNjcoBS0NTYCD9pClnruDphijin/IJY5VANUP61vWzdMcQ4+vfcUoEKW5NOdcc/gP 8LQ8ZKMHJGWh7cieC//06HoEQhQe+N72OVdWUFKOOpOuublBfvh6iMb0IlX5p1hYWWVqiQExSy4W8 kDWugzM2g==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:59012) by pandora.armlinux.org.uk with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1jnffc-0001cC-38; Tue, 23 Jun 2020 10:56:48 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.92) (envelope-from ) id 1jnffa-0000vi-KS; Tue, 23 Jun 2020 10:56:46 +0100 Date: Tue, 23 Jun 2020 10:56:46 +0100 From: Russell King - ARM Linux admin To: Bartosz Golaszewski Cc: Bartosz Golaszewski , Andrew Lunn , Alexandre Belloni , devicetree , Vladimir Oltean , Linux Kernel Mailing List , Fabien Parent , Iyappan Subramanian , Quan Nguyen , Frank Rowand , Florian Fainelli , Jakub Kicinski , Vivien Didelot , Tom Lendacky , Andrew Perepech , Stephane Le Provost , Keyur Chudgar , Jassi Brar , Claudiu Manoil , Mark Brown , "moderated list:ARM/Mediatek SoC..." , Matthias Brugger , Linux ARM , netdev , Ilias Apalodimas , Liam Girdwood , Rob Herring , Philipp Zabel , Pedro Tsai , "David S . Miller" , Heiner Kallweit Subject: Re: [PATCH 14/15] net: phy: add PHY regulator support Message-ID: <20200623095646.GT1551@shell.armlinux.org.uk> References: <20200622093744.13685-1-brgl@bgdev.pl> <20200622093744.13685-15-brgl@bgdev.pl> <20200622132921.GI1551@shell.armlinux.org.uk> <20200623094252.GS1551@shell.armlinux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Tue, Jun 23, 2020 at 11:46:15AM +0200, Bartosz Golaszewski wrote: > wt., 23 cze 2020 o 11:43 Russell King - ARM Linux admin > napisał(a): > > > > On Tue, Jun 23, 2020 at 11:41:11AM +0200, Bartosz Golaszewski wrote: > > > pon., 22 cze 2020 o 15:29 Russell King - ARM Linux admin > > > napisał(a): > > > > > > > > > > [snip!] > > > > > > > > > > > This is likely to cause issues for some PHY drivers. Note that we have > > > > some PHY drivers which register a temperature sensor in the probe > > > > function, which means they can be accessed independently of the lifetime > > > > of the PHY bound to the network driver (which may only be while the > > > > network device is "up".) We certainly do not want hwmon failing just > > > > because the network device is down. > > > > > > > > That's kind of worked around for the reset stuff, because there are two > > > > layers to that: the mdio device layer reset support which knows nothing > > > > of the PHY binding state to the network driver, and the phylib reset > > > > support, but it is not nice. > > > > > > > > > > Regulators are reference counted so if the hwmon driver enables it > > > using mdio_device_power_on() it will stay on even after the PHY driver > > > calls phy_device_power_off(), right? Am I missing something? > > > > If that is true, you will need to audit the PHY drivers to add that. > > > > This change doesn't have any effect on devices which don't have a > regulator assigned in DT though. The one I'm adding in the last patch > is the first to use this. It's quality of implementation. Should we wait for someone else to make use of the new regulator support that has been added with a PHY that uses hwmon, and they don't realise that it breaks hwmon on it, and several kernel versions go by without it being noticed. It will only be a noticable issue when the associated network device is down, and that network device driver detaches from the PHY, so _is_ likely not to be noticed. Or should we do a small amount of work now to properly implement regulator support, which includes a trivial grep for "hwmon" amongst the PHY drivers, and add the necessary call to avoid the regulator being shut off. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!