[PATCH AUTOSEL 5.10 18/20] net: usb: lan78xx: don't modify phy_device state concurrently
From: Sasha Levin <sashal@kernel.org>
Date: 2021-08-10 14:18:27
Also in:
linux-usb, lkml, netdev
Subsystem:
networking drivers, the rest, usb lan78xx ethernet driver, usb networking drivers · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Thangaraj Samynathan, Rengarajan Sundararajan
From: "Ivan T. Ivanov" <redacted> [ Upstream commit 6b67d4d63edece1033972214704c04f36c5be89a ] Currently phy_device state could be left in inconsistent state shown by following alert message[1]. This is because phy_read_status could be called concurrently from lan78xx_delayedwork, phy_state_machine and __ethtool_get_link. Fix this by making sure that phy_device state is updated atomically. [1] lan78xx 1-1.1.1:1.0 eth0: No phy led trigger registered for speed(-1) Signed-off-by: Ivan T. Ivanov <redacted> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> --- drivers/net/usb/lan78xx.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c
index 65b315bc60ab..a5cd42bae962 100644
--- a/drivers/net/usb/lan78xx.c
+++ b/drivers/net/usb/lan78xx.c@@ -1159,7 +1159,7 @@ static int lan78xx_link_reset(struct lan78xx_net *dev) { struct phy_device *phydev = dev->net->phydev; struct ethtool_link_ksettings ecmd; - int ladv, radv, ret; + int ladv, radv, ret, link; u32 buf; /* clear LAN78xx interrupt status */
@@ -1167,9 +1167,12 @@ static int lan78xx_link_reset(struct lan78xx_net *dev) if (unlikely(ret < 0)) return -EIO; + mutex_lock(&phydev->lock); phy_read_status(phydev); + link = phydev->link; + mutex_unlock(&phydev->lock); - if (!phydev->link && dev->link_on) { + if (!link && dev->link_on) { dev->link_on = false; /* reset MAC */
@@ -1182,7 +1185,7 @@ static int lan78xx_link_reset(struct lan78xx_net *dev) return -EIO; del_timer(&dev->stat_monitor); - } else if (phydev->link && !dev->link_on) { + } else if (link && !dev->link_on) { dev->link_on = true; phy_ethtool_ksettings_get(phydev, &ecmd);
@@ -1471,9 +1474,14 @@ static int lan78xx_set_eee(struct net_device *net, struct ethtool_eee *edata) static u32 lan78xx_get_link(struct net_device *net) { + u32 link; + + mutex_lock(&net->phydev->lock); phy_read_status(net->phydev); + link = net->phydev->link; + mutex_unlock(&net->phydev->lock); - return net->phydev->link; + return link; } static void lan78xx_get_drvinfo(struct net_device *net,
--
2.30.2