From mboxrd@z Thu Jan 1 00:00:00 1970 From: Quentin Schulz Subject: [PATCH net v2] net: phy: mscc: fix deadlock in vsc85xx_default_config Date: Fri, 23 Nov 2018 09:16:36 +0100 Message-ID: <20181123081636.18795-1-quentin.schulz@bootlin.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 To: davem@davemloft.net, andrew@lunn.ch, f.fainelli@gmail.com Return-path: Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.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 --- v2: - use phy_modify_paged instead of phy_select_page -> __phy_read -> __phy_write -> phy_restore_page drivers/net/phy/mscc.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/drivers/net/phy/mscc.c b/drivers/net/phy/mscc.c index 62269e578718..4dcf7ad06259 100644 --- a/drivers/net/phy/mscc.c +++ b/drivers/net/phy/mscc.c @@ -810,17 +810,16 @@ 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); + + 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); 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); - out_unlock: - rc = phy_restore_page(phydev, rc, rc > 0 ? 0 : rc); mutex_unlock(&phydev->lock); return rc; -- 2.17.1