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=-5.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham 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 0C98DC43441 for ; Fri, 23 Nov 2018 18:04:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BA79720865 for ; Fri, 23 Nov 2018 18:04:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b="eHT7ubda" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BA79720865 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lunn.ch Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2441111AbeKXEtU (ORCPT ); Fri, 23 Nov 2018 23:49:20 -0500 Received: from vps0.lunn.ch ([185.16.172.187]:47254 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730633AbeKXEtU (ORCPT ); Fri, 23 Nov 2018 23:49:20 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date; bh=dFQ6lTpKyBaHJddzTcdgW5OlLcPBdBvxdHEB9G6yEtA=; b=eHT7ubdaeapOGbq7O6JLkJBmtwtmZcTjm61fEaLErsBs0wmNEhYFGBBiiWD7ubJqTogbx/4DpqtTAF57Fnj36KIKJGcfR5nWrSgnz86B/NrnzC3MvPtSI4NBdQf6VyTe+fiX8ezTbtEG9xRDcDoqZTYzq2E0pwzAXikHnaguPkw=; Received: from andrew by vps0.lunn.ch with local (Exim 4.84_2) (envelope-from ) id 1gQFo6-0001ZS-Kv; Fri, 23 Nov 2018 19:03:58 +0100 Date: Fri, 23 Nov 2018 19:03:58 +0100 From: Andrew Lunn To: Quentin Schulz Cc: davem@davemloft.net, f.fainelli@gmail.com, allan.nielsen@microchip.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, thomas.petazzoni@bootlin.com, alexandre.belloni@bootlin.com Subject: Re: [PATCH net v3] net: phy: mscc: fix deadlock in vsc85xx_default_config Message-ID: <20181123180358.GC5273@lunn.ch> References: <20181123180151.14183-1-quentin.schulz@bootlin.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181123180151.14183-1-quentin.schulz@bootlin.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Nov 23, 2018 at 07:01:51PM +0100, Quentin Schulz wrote: > The vsc85xx_default_config function called in the vsc85xx_config_init > function which is used by VSC8530, VSC8531, VSC8540 and VSC8541 PHYs > mistakenly calls phy_read and phy_write in-between phy_select_page and > phy_restore_page. > > phy_select_page and phy_restore_page actually take and release the MDIO > bus lock and phy_write and phy_read take and release the lock to write > or read to a PHY register. > > Let's fix this deadlock by using phy_modify_paged which handles > correctly a read followed by a write in a non-standard page. > > Fixes: 6a0bfbbe20b0 ("net: phy: mscc: migrate to phy_select/restore_page functions") > > Signed-off-by: Quentin Schulz Reviewed-by: Andrew Lunn Andrew