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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 EC71AC43441 for ; Fri, 23 Nov 2018 18:02:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C2E1920865 for ; Fri, 23 Nov 2018 18:02:04 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C2E1920865 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bootlin.com 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 S2441087AbeKXErU (ORCPT ); Fri, 23 Nov 2018 23:47:20 -0500 Received: from mail.bootlin.com ([62.4.15.54]:40432 "EHLO mail.bootlin.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730633AbeKXErU (ORCPT ); Fri, 23 Nov 2018 23:47:20 -0500 Received: by mail.bootlin.com (Postfix, from userid 110) id DE9A520D92; Fri, 23 Nov 2018 19:02:00 +0100 (CET) Received: from qschulz.home (lfbn-1-10589-128.w90-89.abo.wanadoo.fr [90.89.181.128]) by mail.bootlin.com (Postfix) with ESMTPSA id 9DCD320736; Fri, 23 Nov 2018 19:02:00 +0100 (CET) From: Quentin Schulz To: davem@davemloft.net, andrew@lunn.ch, f.fainelli@gmail.com Cc: allan.nielsen@microchip.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, thomas.petazzoni@bootlin.com, alexandre.belloni@bootlin.com, Quentin Schulz Subject: [PATCH net v3] net: phy: mscc: fix deadlock in vsc85xx_default_config Date: Fri, 23 Nov 2018 19:01:51 +0100 Message-Id: <20181123180151.14183-1-quentin.schulz@bootlin.com> X-Mailer: git-send-email 2.17.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- v3: - remove useless goto label and condition, v2: - use phy_modify_paged instead of phy_select_page -> __phy_read -> __phy_write -> phy_restore_page drivers/net/phy/mscc.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-) diff --git a/drivers/net/phy/mscc.c b/drivers/net/phy/mscc.c index 62269e578718..cfe680f78a3f 100644 --- a/drivers/net/phy/mscc.c +++ b/drivers/net/phy/mscc.c @@ -810,17 +810,13 @@ static int vsc85xx_default_config(struct phy_device *phydev) phydev->mdix_ctrl = ETH_TP_MDI_AUTO; mutex_lock(&phydev->lock); - rc = phy_select_page(phydev, MSCC_PHY_PAGE_EXTENDED_2); - if (rc < 0) - goto out_unlock; - reg_val = phy_read(phydev, MSCC_PHY_RGMII_CNTL); - reg_val &= ~(RGMII_RX_CLK_DELAY_MASK); - reg_val |= (RGMII_RX_CLK_DELAY_1_1_NS << RGMII_RX_CLK_DELAY_POS); - phy_write(phydev, MSCC_PHY_RGMII_CNTL, reg_val); + reg_val = RGMII_RX_CLK_DELAY_1_1_NS << RGMII_RX_CLK_DELAY_POS; + + rc = phy_modify_paged(phydev, MSCC_PHY_PAGE_EXTENDED_2, + MSCC_PHY_RGMII_CNTL, RGMII_RX_CLK_DELAY_MASK, + reg_val); -out_unlock: - rc = phy_restore_page(phydev, rc, rc > 0 ? 0 : rc); mutex_unlock(&phydev->lock); return rc; -- 2.17.1