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 BED0AC6FA82 for ; Sun, 18 Sep 2022 20:55:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229479AbiIRUzV (ORCPT ); Sun, 18 Sep 2022 16:55:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42812 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229458AbiIRUzV (ORCPT ); Sun, 18 Sep 2022 16:55:21 -0400 X-Greylist: delayed 6102 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Sun, 18 Sep 2022 13:55:18 PDT Received: from bmailout1.hostsharing.net (bmailout1.hostsharing.net [83.223.95.100]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B056211444; Sun, 18 Sep 2022 13:55:18 -0700 (PDT) Received: from h08.hostsharing.net (h08.hostsharing.net [IPv6:2a01:37:1000::53df:5f1c:0]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "*.hostsharing.net", Issuer "RapidSSL TLS DV RSA Mixed SHA256 2020 CA-1" (verified OK)) by bmailout1.hostsharing.net (Postfix) with ESMTPS id F059F300002D5; Sun, 18 Sep 2022 22:55:16 +0200 (CEST) Received: by h08.hostsharing.net (Postfix, from userid 100393) id D3C8827C72; Sun, 18 Sep 2022 22:55:16 +0200 (CEST) Date: Sun, 18 Sep 2022 22:55:16 +0200 From: Lukas Wunner To: Florian Fainelli Cc: Marek Szyprowski , "David S. Miller" , Jakub Kicinski , Paolo Abeni , Eric Dumazet , netdev@vger.kernel.org, linux-usb@vger.kernel.org, Steve Glendinning , UNGLinuxDriver@microchip.com, Oliver Neukum , Andre Edich , Oleksij Rempel , Martyn Welch , Gabriel Hojda , Christoph Fritz , Lino Sanfilippo , Philipp Rosenberger , Heiner Kallweit , Andrew Lunn , Russell King , Ferry Toth , Krzysztof Kozlowski , 'Linux Samsung SOC' Subject: Re: [PATCH net-next v3 5/7] usbnet: smsc95xx: Forward PHY interrupts to PHY driver to avoid polling Message-ID: <20220918205516.GA13914@wunner.de> References: <20220519190841.GA30869@wunner.de> <31baa38c-b2c7-10cd-e9cd-eee140f01788@samsung.com> <20220826071924.GA21264@wunner.de> <2b1a1588-505e-dff3-301d-bfc1fb14d685@samsung.com> <20220826075331.GA32117@wunner.de> <093730dd-2f2c-bd0b-bd13-b97f8a2898bd@samsung.com> <81c0f21f-f8f1-f7b3-c52f-c6a564c6a445@samsung.com> <20220918191333.GA2107@wunner.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-samsung-soc@vger.kernel.org On Sun, Sep 18, 2022 at 01:41:13PM -0700, Florian Fainelli wrote: > On 9/18/2022 12:13 PM, Lukas Wunner wrote: > > On Mon, Aug 29, 2022 at 01:40:05PM +0200, Marek Szyprowski wrote: > > > I've finally traced what has happened. I've double checked and indeed > > > the 1758bde2e4aa commit fixed the issue on next-20220516 kernel and as > > > such it has been merged to linus tree. Then the commit 744d23c71af3 > > > ("net: phy: Warn about incorrect mdio_bus_phy_resume() state") has been > > > merged to linus tree, which triggers a new warning during the > > > suspend/resume cycle with smsc95xx driver. Please note, that the > > > smsc95xx still works fine regardless that warning. However it look that > > > the commit 1758bde2e4aa only hide a real problem, which the commit > > > 744d23c71af3 warns about. > > > > > > Probably a proper fix for smsc95xx driver is to call phy_stop/start > > > during suspend/resume cycle, like in similar patches for other drivers: > > > > > > https://lore.kernel.org/all/20220825023951.3220-1-f.fainelli@gmail.com/ > > > > No, smsc95xx.c relies on mdio_bus_phy_{suspend,resume}() and there's > > no need to call phy_{stop,start}() > > > 744d23c71af3 was flawed and 6dbe852c379f has already fixed a portion > > of the fallout. > > > > However the WARN() condition still seems too broad and causes false > > positives such as in your case. In particular, mdio_bus_phy_suspend() > > may leave the device in PHY_UP state, so that's a legal state that > > needs to be exempted from the WARN(). > > How is that a legal state when the PHY should be suspended? Even if we are > interrupt driven, the state machine should be stopped, does not mean that > Wake-on-LAN or other activity interrupts should be disabled. mdio_bus_phy_suspend() phy_stop_machine() phydev->state = PHY_UP # if (phydev->state >= PHY_UP) So apparently PHY_UP is a legal state for a suspended PHY. > > Does the issue still appear even after 6dbe852c379f? > > > > If it does, could you test whether exempting PHY_UP silences the > > gratuitous WARN splat? I.e.: > > If you allow PHY_UP, then the warning becomes effectively useless, so I > don't believe this is quite what you want to do here. Hm, maybe the WARN() should be dropped altogether? Thanks, Lukas