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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 B2E78C433E0 for ; Tue, 5 Jan 2021 14:11:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7ED8320770 for ; Tue, 5 Jan 2021 14:11:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729093AbhAEOLJ (ORCPT ); Tue, 5 Jan 2021 09:11:09 -0500 Received: from vps0.lunn.ch ([185.16.172.187]:50172 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726961AbhAEOLI (ORCPT ); Tue, 5 Jan 2021 09:11:08 -0500 Received: from andrew by vps0.lunn.ch with local (Exim 4.94) (envelope-from ) id 1kwn2L-00GAxa-O1; Tue, 05 Jan 2021 15:10:13 +0100 Date: Tue, 5 Jan 2021 15:10:13 +0100 From: Andrew Lunn To: Geert Uytterhoeven Cc: Ioana Ciornei , Heiner Kallweit , "David S . Miller" , Jakub Kicinski , Russell King , Wolfram Sang , Sergei Shtylyov , "netdev@vger.kernel.org" , "linux-renesas-soc@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] [RFC] net: phy: Fix reboot crash if CONFIG_IP_PNP is not set Message-ID: References: <20210104122415.1263541-1-geert+renesas@glider.be> <20210104145331.tlwjwbzey5i4vgvp@skbuf> <20210104170112.hn6t3kojhifyuaf6@skbuf> <20210104184341.szvnl24wnfnxg4k7@skbuf> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > I added a statically-linked ethtool binary to my initramfs, and can > confirm that retrieving the PHY statistics does not access the PHY > registers when the device is suspended: > > # ethtool --phy-statistics eth0 > no stats available > # ifconfig eth0 up > # ethtool --phy-statistics eth0 > PHY statistics: > phy_receive_errors: 0 > phy_idle_errors: 0 > # > > In the past, we've gone to great lengths to avoid accessing the PHY > registers when the device is suspended, usually in the statistics > handling (see e.g. [1][2]). I would argue that is the wrong approach. The PHY device is a device. It has its own lifetime. You would not suspend a PCI bus controller without first suspending all PCI devices on the bus etc. > +static int sh_mdiobb_read(struct mii_bus *bus, int phy, int reg) > +{ > + struct bb_info *bb = container_of(bus->priv, struct bb_info, ctrl); mii_bus->parent should give you dev, so there is no need to add it to bb_info. > + /* Wrap accessors with Runtime PM-aware ops */ > + bitbang->read = mdp->mii_bus->read; > + bitbang->write = mdp->mii_bus->write; > + mdp->mii_bus->read = sh_mdiobb_read; > + mdp->mii_bus->write = sh_mdiobb_write; I did wonder about just exporting the two functions so you can directly call them. Otherwise, this looks good. Andrew