[PATCH net v3 2/3] net: phy: Check phydev->drv

[Florian Fainelli]

In preparation for supporting driver bind/unbind properly, sprinkle checks on
phydev->drv where we may call into PHYLIB from user-space or other parts of the
kernel.

Suggested-by: Russell King <rmk+ker...@armlinux.org.uk>
Signed-off-by: Florian Fainelli <f.faine...@gmail.com>
---
 drivers/net/phy/phy.c        | 26 ++++++++++++++++++++++----
 drivers/net/phy/phy_device.c |  2 +-
 include/linux/phy.h          |  3 +++
 3 files changed, 26 insertions(+), 5 deletions(-)

diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index 7cc1b7dcfe05..d6f7838455dd 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -580,7 +580,7 @@ int phy_mii_ioctl(struct phy_device *phydev, struct ifreq 
*ifr, int cmd)
                return 0;
 
        case SIOCSHWTSTAMP:
-               if (phydev->drv->hwtstamp)
+               if (phydev->drv && phydev->drv->hwtstamp)
                        return phydev->drv->hwtstamp(phydev, ifr);
                /* fall through */
 
@@ -603,6 +603,9 @@ int phy_start_aneg(struct phy_device *phydev)
 {
        int err;
 
+       if (!phydev->drv)
+               return -EIO;
+
        mutex_lock(&phydev->lock);
 
        if (AUTONEG_DISABLE == phydev->autoneg)
@@ -975,7 +978,7 @@ void phy_state_machine(struct work_struct *work)
 
        old_state = phydev->state;
 
-       if (phydev->drv->link_change_notify)
+       if (phydev->drv && phydev->drv->link_change_notify)
                phydev->drv->link_change_notify(phydev);
 
        switch (phydev->state) {
@@ -1286,6 +1289,9 @@ EXPORT_SYMBOL(phy_write_mmd_indirect);
  */
 int phy_init_eee(struct phy_device *phydev, bool clk_stop_enable)
 {
+       if (!phydev->drv)
+               return -EIO;
+
        /* According to 802.3az,the EEE is supported only in full duplex-mode.
         * Also EEE feature is active when core is operating with MII, GMII
         * or RGMII (all kinds). Internal PHYs are also allowed to proceed and
@@ -1363,6 +1369,9 @@ EXPORT_SYMBOL(phy_init_eee);
  */
 int phy_get_eee_err(struct phy_device *phydev)
 {
+       if (!phydev->drv)
+               return -EIO;
+
        return phy_read_mmd_indirect(phydev, MDIO_PCS_EEE_WK_ERR, MDIO_MMD_PCS);
 }
 EXPORT_SYMBOL(phy_get_eee_err);
@@ -1379,6 +1388,9 @@ int phy_ethtool_get_eee(struct phy_device *phydev, struct 
ethtool_eee *data)
 {
        int val;
 
+       if (!phydev->drv)
+               return -EIO;
+
        /* Get Supported EEE */
        val = phy_read_mmd_indirect(phydev, MDIO_PCS_EEE_ABLE, MDIO_MMD_PCS);
        if (val < 0)
@@ -1412,6 +1424,9 @@ int phy_ethtool_set_eee(struct phy_device *phydev, struct 
ethtool_eee *data)
 {
        int val = ethtool_adv_to_mmd_eee_adv_t(data->advertised);
 
+       if (!phydev->drv)
+               return -EIO;
+
        /* Mask prohibited EEE modes */
        val &= ~phydev->eee_broken_modes;
 
@@ -1423,7 +1438,7 @@ EXPORT_SYMBOL(phy_ethtool_set_eee);
 
 int phy_ethtool_set_wol(struct phy_device *phydev, struct ethtool_wolinfo *wol)
 {
-       if (phydev->drv->set_wol)
+       if (phydev->drv && phydev->drv->set_wol)
                return phydev->drv->set_wol(phydev, wol);
 
        return -EOPNOTSUPP;
@@ -1432,7 +1447,7 @@ EXPORT_SYMBOL(phy_ethtool_set_wol);
 
 void phy_ethtool_get_wol(struct phy_device *phydev, struct ethtool_wolinfo 
*wol)
 {
-       if (phydev->drv->get_wol)
+       if (phydev->drv && phydev->drv->get_wol)
                phydev->drv->get_wol(phydev, wol);
 }
 EXPORT_SYMBOL(phy_ethtool_get_wol);
@@ -1468,6 +1483,9 @@ int phy_ethtool_nway_reset(struct net_device *ndev)
        if (!phydev)
                return -ENODEV;
 
+       if (!phydev->drv)
+               return -EIO;
+
        return genphy_restart_aneg(phydev);
 }
 EXPORT_SYMBOL(phy_ethtool_nway_reset);
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index d63d190a95ef..40675b9706ae 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -1790,7 +1790,7 @@ static int phy_remove(struct device *dev)
        phydev->state = PHY_DOWN;
        mutex_unlock(&phydev->lock);
 
-       if (phydev->drv->remove)
+       if (phydev->drv && phydev->drv->remove)
                phydev->drv->remove(phydev);
        phydev->drv = NULL;
 
diff --git a/include/linux/phy.h b/include/linux/phy.h
index 7fc1105605bf..231e07bb0d76 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -802,6 +802,9 @@ int phy_stop_interrupts(struct phy_device *phydev);
 
 static inline int phy_read_status(struct phy_device *phydev)
 {
+       if (!phydev->drv)
+               return -EIO;
+
        return phydev->drv->read_status(phydev);
 }
 
-- 
2.9.3