diff options
Diffstat (limited to 'net/core/net-sysfs.c')
| -rw-r--r-- | net/core/net-sysfs.c | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index fccaa5bac0..a09d507c5b 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -193,11 +193,22 @@ static ssize_t carrier_show(struct device *dev, struct device_attribute *attr, char *buf) { struct net_device *netdev = to_net_dev(dev); + int ret = -EINVAL; - if (netif_running(netdev)) - return sysfs_emit(buf, fmt_dec, !!netif_carrier_ok(netdev)); + if (!rtnl_trylock()) + return restart_syscall(); - return -EINVAL; + if (netif_running(netdev)) { + /* Synchronize carrier state with link watch, + * see also rtnl_getlink(). + */ + linkwatch_sync_dev(netdev); + + ret = sysfs_emit(buf, fmt_dec, !!netif_carrier_ok(netdev)); + } + rtnl_unlock(); + + return ret; } static DEVICE_ATTR_RW(carrier); |