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authorSergei Miroshnichenko <sergeimir@emcraft.com>2016-09-07 16:51:12 +0300
committerMarc Kleine-Budde <mkl@pengutronix.de>2016-09-22 10:01:21 +0200
commit9abefcb1aaa58b9d5aa40a8bb12c87d02415e4c8 (patch)
treeff081f6644b855d62aae2a48a8f6f4a8c00d7a78 /drivers
parent7e32b44361abc77fbc01f2b97b045c405b2583e5 (diff)
downloadlinux-stericsson-9abefcb1aaa58b9d5aa40a8bb12c87d02415e4c8.tar.gz
can: dev: fix deadlock reported after bus-off
A timer was used to restart after the bus-off state, leading to a relatively large can_restart() executed in an interrupt context, which in turn sets up pinctrl. When this happens during system boot, there is a high probability of grabbing the pinctrl_list_mutex, which is locked already by the probe() of other device, making the kernel suspect a deadlock condition [1]. To resolve this issue, the restart_timer is replaced by a delayed work. [1] https://github.com/victronenergy/venus/issues/24 Signed-off-by: Sergei Miroshnichenko <sergeimir@emcraft.com> Cc: linux-stable <stable@vger.kernel.org> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/net/can/dev.c27
1 files changed, 17 insertions, 10 deletions
diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c
index e21f7cc5ae4d..8d6208c0b400 100644
--- a/drivers/net/can/dev.c
+++ b/drivers/net/can/dev.c
@@ -21,6 +21,7 @@
#include <linux/slab.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
+#include <linux/workqueue.h>
#include <linux/can.h>
#include <linux/can/dev.h>
#include <linux/can/skb.h>
@@ -501,9 +502,8 @@ EXPORT_SYMBOL_GPL(can_free_echo_skb);
/*
* CAN device restart for bus-off recovery
*/
-static void can_restart(unsigned long data)
+static void can_restart(struct net_device *dev)
{
- struct net_device *dev = (struct net_device *)data;
struct can_priv *priv = netdev_priv(dev);
struct net_device_stats *stats = &dev->stats;
struct sk_buff *skb;
@@ -543,6 +543,14 @@ restart:
netdev_err(dev, "Error %d during restart", err);
}
+static void can_restart_work(struct work_struct *work)
+{
+ struct delayed_work *dwork = to_delayed_work(work);
+ struct can_priv *priv = container_of(dwork, struct can_priv, restart_work);
+
+ can_restart(priv->dev);
+}
+
int can_restart_now(struct net_device *dev)
{
struct can_priv *priv = netdev_priv(dev);
@@ -556,8 +564,8 @@ int can_restart_now(struct net_device *dev)
if (priv->state != CAN_STATE_BUS_OFF)
return -EBUSY;
- /* Runs as soon as possible in the timer context */
- mod_timer(&priv->restart_timer, jiffies);
+ cancel_delayed_work_sync(&priv->restart_work);
+ can_restart(dev);
return 0;
}
@@ -578,8 +586,8 @@ void can_bus_off(struct net_device *dev)
netif_carrier_off(dev);
if (priv->restart_ms)
- mod_timer(&priv->restart_timer,
- jiffies + (priv->restart_ms * HZ) / 1000);
+ schedule_delayed_work(&priv->restart_work,
+ msecs_to_jiffies(priv->restart_ms));
}
EXPORT_SYMBOL_GPL(can_bus_off);
@@ -688,6 +696,7 @@ struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max)
return NULL;
priv = netdev_priv(dev);
+ priv->dev = dev;
if (echo_skb_max) {
priv->echo_skb_max = echo_skb_max;
@@ -697,7 +706,7 @@ struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max)
priv->state = CAN_STATE_STOPPED;
- init_timer(&priv->restart_timer);
+ INIT_DELAYED_WORK(&priv->restart_work, can_restart_work);
return dev;
}
@@ -778,8 +787,6 @@ int open_candev(struct net_device *dev)
if (!netif_carrier_ok(dev))
netif_carrier_on(dev);
- setup_timer(&priv->restart_timer, can_restart, (unsigned long)dev);
-
return 0;
}
EXPORT_SYMBOL_GPL(open_candev);
@@ -794,7 +801,7 @@ void close_candev(struct net_device *dev)
{
struct can_priv *priv = netdev_priv(dev);
- del_timer_sync(&priv->restart_timer);
+ cancel_delayed_work_sync(&priv->restart_work);
can_flush_echo_skb(dev);
}
EXPORT_SYMBOL_GPL(close_candev);