From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933767AbbIVR6n (ORCPT ); Tue, 22 Sep 2015 13:58:43 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:43054 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759380AbbIVRyN (ORCPT ); Tue, 22 Sep 2015 13:54:13 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Russell King , "David S. Miller" , Kamal Mostafa Subject: [PATCH 3.19.y-ckt 093/102] net: phy: add locking to phy_read_mmd_indirect()/phy_write_mmd_indirect() Date: Tue, 22 Sep 2015 10:52:29 -0700 Message-Id: <1442944358-1248-94-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1442944358-1248-1-git-send-email-kamal@canonical.com> References: <1442944358-1248-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.19 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.19.8-ckt7 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Russell King commit 05a7f582be961824d62a7f4a817f3783148b5f8a upstream. The phy layer is missing locking for the above two functions - it has been observed that two threads (userspace and the phy worker thread) can race, entering the bus ->write or ->read functions simultaneously. This causes the FEC driver to initialise a completion while another thread is waiting on it or while the interrupt is calling complete() on it, which causes spinlock unlock-without-lock, spinlock lockups, and completion timeouts. Fixes: a59a4d192 ("phy: add the EEE support and the way to access to the MMD registers.") Fixes: 0c1d77dfb ("net: libphy: Add phy specific function to access mmd phy registers") Signed-off-by: Russell King Acked-by: Florian Fainelli Signed-off-by: David S. Miller Signed-off-by: Kamal Mostafa --- drivers/net/phy/phy.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c index 91d6d03..15a7387 100644 --- a/drivers/net/phy/phy.c +++ b/drivers/net/phy/phy.c @@ -993,10 +993,14 @@ int phy_read_mmd_indirect(struct phy_device *phydev, int prtad, int value = -1; if (phydrv->read_mmd_indirect == NULL) { - mmd_phy_indirect(phydev->bus, prtad, devad, addr); + struct mii_bus *bus = phydev->bus; + + mutex_lock(&bus->mdio_lock); + mmd_phy_indirect(bus, prtad, devad, addr); /* Read the content of the MMD's selected register */ - value = phydev->bus->read(phydev->bus, addr, MII_MMD_DATA); + value = bus->read(bus, addr, MII_MMD_DATA); + mutex_unlock(&bus->mdio_lock); } else { value = phydrv->read_mmd_indirect(phydev, prtad, devad, addr); } @@ -1026,10 +1030,14 @@ void phy_write_mmd_indirect(struct phy_device *phydev, int prtad, struct phy_driver *phydrv = phydev->drv; if (phydrv->write_mmd_indirect == NULL) { - mmd_phy_indirect(phydev->bus, prtad, devad, addr); + struct mii_bus *bus = phydev->bus; + + mutex_lock(&bus->mdio_lock); + mmd_phy_indirect(bus, prtad, devad, addr); /* Write the data into MMD's selected register */ - phydev->bus->write(phydev->bus, addr, MII_MMD_DATA, data); + bus->write(bus, addr, MII_MMD_DATA, data); + mutex_unlock(&bus->mdio_lock); } else { phydrv->write_mmd_indirect(phydev, prtad, devad, addr, data); } -- 1.9.1