From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kedareswara rao Appana Subject: [PATCH 2/2] net: phy: Fix race conditions in the driver Date: Fri, 19 Aug 2016 18:18:11 +0530 Message-ID: <1471610891-13353-2-git-send-email-appanad@xilinx.com> References: <1471610891-13353-1-git-send-email-appanad@xilinx.com> Mime-Version: 1.0 Content-Type: text/plain Cc: , , To: , , , , Return-path: Received: from mail-dm3nam03on0050.outbound.protection.outlook.com ([104.47.41.50]:15496 "EHLO NAM03-DM3-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754558AbcHSMtq (ORCPT ); Fri, 19 Aug 2016 08:49:46 -0400 In-Reply-To: <1471610891-13353-1-git-send-email-appanad@xilinx.com> Sender: netdev-owner@vger.kernel.org List-ID: This patch fixes the below race conditions in the driver. ---> Fix Opps after unload the driver as a module ---> Use spin locks where relevant. ---> Take reference on the external phy to prevent issues when phy driver is unloaded. Reported-by: Andrew Lunn Signed-off-by: Kedareswara rao Appana --- drivers/net/phy/xilinx_gmii2rgmii.c | 32 +++++++++++++++++++++++++++++++- 1 file changed, 31 insertions(+), 1 deletion(-) diff --git a/drivers/net/phy/xilinx_gmii2rgmii.c b/drivers/net/phy/xilinx_gmii2rgmii.c index 7336fd0..cdd9d95 100644 --- a/drivers/net/phy/xilinx_gmii2rgmii.c +++ b/drivers/net/phy/xilinx_gmii2rgmii.c @@ -34,6 +34,7 @@ struct gmii2rgmii { struct phy_driver *phy_drv; struct phy_driver conv_phy_drv; int addr; + spinlock_t phy_lock; }; static int xgmiitorgmii_read_status(struct phy_device *phydev) @@ -55,7 +56,7 @@ static int xgmiitorgmii_read_status(struct phy_device *phydev) val |= BMCR_SPEED1000; else if (phydev->speed == SPEED_100) val |= BMCR_SPEED100; - else + else if (phydev->speed == SPEED_10) val |= BMCR_SPEED10; err = mdiobus_write(phydev->mdio.bus, priv->addr, XILINX_GMII2RGMII_REG, @@ -71,6 +72,8 @@ int xgmiitorgmii_probe(struct mdio_device *mdiodev) struct device *dev = &mdiodev->dev; struct device_node *np = dev->of_node, *phy_node; struct gmii2rgmii *priv; + struct mii_bus *bus; + unsigned long flags; priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); if (!priv) @@ -88,17 +91,43 @@ int xgmiitorgmii_probe(struct mdio_device *mdiodev) return -EPROBE_DEFER; } + spin_lock_init(&priv->phy_lock); + + bus = priv->phy_dev->mdio.bus; + if (!try_module_get(bus->owner)) { + dev_err(dev, "failed to get the bus module\n"); + return -EIO; + } + + get_device(&priv->phy_dev->mdio.dev); + priv->addr = mdiodev->addr; priv->phy_drv = priv->phy_dev->drv; memcpy(&priv->conv_phy_drv, priv->phy_dev->drv, sizeof(struct phy_driver)); priv->conv_phy_drv.read_status = xgmiitorgmii_read_status; priv->phy_dev->priv = priv; + spin_lock_irqsave(&priv->phy_lock, flags); priv->phy_dev->drv = &priv->conv_phy_drv; + spin_unlock_irqrestore(&priv->phy_lock, flags); + + dev_set_drvdata(dev, priv); return 0; } +static void xgmiitorgmii_remove(struct mdio_device *mdiodev) +{ + struct gmii2rgmii *priv = dev_get_drvdata(&mdiodev->dev); + struct mii_bus *bus; + + bus = priv->phy_dev->mdio.bus; + + put_device(&priv->phy_dev->mdio.dev); + module_put(bus->owner); + phy_disconnect(priv->phy_dev); +} + static const struct of_device_id xgmiitorgmii_of_match[] = { { .compatible = "xlnx,gmii-to-rgmii-1.0" }, {}, @@ -107,6 +136,7 @@ MODULE_DEVICE_TABLE(of, xgmiitorgmii_of_match); static struct mdio_driver xgmiitorgmii_driver = { .probe = xgmiitorgmii_probe, + .remove = xgmiitorgmii_remove, .mdiodrv.driver = { .name = "xgmiitorgmii", .of_match_table = xgmiitorgmii_of_match, -- 2.1.2