From 3fa528b7682e73e906266bcd43728b8f923bf9b2 Mon Sep 17 00:00:00 2001 From: Quentin Schulz Date: Fri, 23 Nov 2018 19:01:51 +0100 Subject: [PATCH] net: phy: mscc: fix deadlock in vsc85xx_default_config 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 Signed-off-by: David S. Miller --- 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 a2e59f4f6f01..7cae17517744 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;