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authorSekhar Nori <nsekhar@ti.com>2017-04-03 15:04:28 +0300
committerDavid S. Miller <davem@davemloft.net>2017-04-04 20:33:33 +0300
commit30c57f073449e09ae42f908bfff56c08c8751a6f (patch)
tree5a1316ef175e9b93befe4eee447c339aa60a8f74 /drivers/net
parent249ee819e24c180909f43c1173c8ef6724d21faf (diff)
downloadlinux-30c57f073449e09ae42f908bfff56c08c8751a6f.tar.xz
net: ethernet: ti: cpsw: fix race condition during open()
TI's cpsw driver handles both OF and non-OF case for phy connect. Unfortunately of_phy_connect() returns NULL on error while phy_connect() returns ERR_PTR(). To handle this, cpsw_slave_open() overrides the return value from phy_connect() to make it NULL or error. This leaves a small window, where cpsw_adjust_link() may be invoked for a slave while slave->phy pointer is temporarily set to -ENODEV (or some other error) before it is finally set to NULL. _cpsw_adjust_link() only handles the NULL case, and an oops results when ERR_PTR() is seen by it. Note that cpsw_adjust_link() checks PHY status for each slave whenever it is invoked. It can so happen that even though phy_connect() for a given slave returns error, _cpsw_adjust_link() is still called for that slave because the link status of another slave changed. Fix this by using a temporary pointer to store return value of {of_}phy_connect() and do a one-time write to slave->phy. Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com> Reported-by: Yan Liu <yan-liu@ti.com> Signed-off-by: Sekhar Nori <nsekhar@ti.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net')
-rw-r--r--drivers/net/ethernet/ti/cpsw.c14
1 files changed, 8 insertions, 6 deletions
diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
index 58cdc066ef2c..fa674a8bda0c 100644
--- a/drivers/net/ethernet/ti/cpsw.c
+++ b/drivers/net/ethernet/ti/cpsw.c
@@ -1267,6 +1267,7 @@ static void soft_reset_slave(struct cpsw_slave *slave)
static void cpsw_slave_open(struct cpsw_slave *slave, struct cpsw_priv *priv)
{
u32 slave_port;
+ struct phy_device *phy;
struct cpsw_common *cpsw = priv->cpsw;
soft_reset_slave(slave);
@@ -1300,27 +1301,28 @@ static void cpsw_slave_open(struct cpsw_slave *slave, struct cpsw_priv *priv)
1 << slave_port, 0, 0, ALE_MCAST_FWD_2);
if (slave->data->phy_node) {
- slave->phy = of_phy_connect(priv->ndev, slave->data->phy_node,
+ phy = of_phy_connect(priv->ndev, slave->data->phy_node,
&cpsw_adjust_link, 0, slave->data->phy_if);
- if (!slave->phy) {
+ if (!phy) {
dev_err(priv->dev, "phy \"%s\" not found on slave %d\n",
slave->data->phy_node->full_name,
slave->slave_num);
return;
}
} else {
- slave->phy = phy_connect(priv->ndev, slave->data->phy_id,
+ phy = phy_connect(priv->ndev, slave->data->phy_id,
&cpsw_adjust_link, slave->data->phy_if);
- if (IS_ERR(slave->phy)) {
+ if (IS_ERR(phy)) {
dev_err(priv->dev,
"phy \"%s\" not found on slave %d, err %ld\n",
slave->data->phy_id, slave->slave_num,
- PTR_ERR(slave->phy));
- slave->phy = NULL;
+ PTR_ERR(phy));
return;
}
}
+ slave->phy = phy;
+
phy_attached_info(slave->phy);
phy_start(slave->phy);