diff options
authorMichael Marineau <mike@marineau.org>2009-01-04 17:18:51 -0800
committerDavid S. Miller <davem@davemloft.net>2009-01-04 17:18:51 -0800
commit22604c866889c4b2e12b73cbf1683bda1b72a313 (patch)
parent745417e20684e4951afcabfe74583a3884e54980 (diff)
net: Fix for initial link state in 2.6.28
From: Michael Marineau <mike@marineau.org> Commit b47300168e770b60ab96c8924854c3b0eb4260eb "Do not fire linkwatch events until the device is registered." was made as a workaround for drivers that call netif_carrier_off before registering the device. Unfortunately this causes these drivers to incorrectly report their link status as IF_OPER_UNKNOWN which can falsely set the IFF_RUNNING flag when the interface is first brought up. This issues was previously pointed out[1] but was dismissed saying that IFF_RUNNING is not related to the link status. From my digging IFF_RUNNING, as reported to userspace, is based on the link state. It is set based on __LINK_STATE_START and IF_OPER_UP or IF_OPER_UNKNOWN. See [2], [3], and [4]. (Whether or not the kernel has IFF_RUNNING set in flags is not reported to user space so it may well be independent of the link, I don't know if and when it may get set.) The end result depends slightly depending on the driver. The the two I tested were e1000e and b44. With e1000e if the system is booted without a network cable attached the interface will falsely report RUNNING when it is brought up causing NetworkManager to attempt to start it and eventually time out. With b44 when the system is booted with a network cable attached and brought up with dhcpcd it will time out the first time. The attached patch that will still set the operstate variable correctly to IF_OPER_UP/DOWN/etc when linkwatch_fire_event is called but then return rather than skipping the linkwatch_fire_event call entirely as the previous fix did. (sorry it isn't inline, I don't have a patch friendly email client at the moment) Signed-off-by: David S. Miller <davem@davemloft.net>
2 files changed, 6 insertions, 5 deletions
diff --git a/net/core/link_watch.c b/net/core/link_watch.c
index bf8f7af699d..1e401e12dc7 100644
--- a/net/core/link_watch.c
+++ b/net/core/link_watch.c
@@ -178,7 +178,6 @@ static void __linkwatch_run_queue(int urgent_only)
clear_bit(__LINK_STATE_LINKWATCH_PENDING, &dev->state);
- rfc2863_policy(dev);
if (dev->flags & IFF_UP) {
if (netif_carrier_ok(dev))
@@ -215,6 +214,12 @@ void linkwatch_fire_event(struct net_device *dev)
bool urgent = linkwatch_urgent_event(dev);
+ rfc2863_policy(dev);
+ /* Some drivers call netif_carrier_off early */
+ if (dev->reg_state == NETREG_UNINITIALIZED)
+ return;
if (!test_and_set_bit(__LINK_STATE_LINKWATCH_PENDING, &dev->state)) {
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 5f5efe4e607..23a8e6141a0 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -270,8 +270,6 @@ static void dev_watchdog_down(struct net_device *dev)
void netif_carrier_on(struct net_device *dev)
if (test_and_clear_bit(__LINK_STATE_NOCARRIER, &dev->state)) {
- if (dev->reg_state == NETREG_UNINITIALIZED)
- return;
if (netif_running(dev))
@@ -288,8 +286,6 @@ EXPORT_SYMBOL(netif_carrier_on);
void netif_carrier_off(struct net_device *dev)
if (!test_and_set_bit(__LINK_STATE_NOCARRIER, &dev->state)) {
- if (dev->reg_state == NETREG_UNINITIALIZED)
- return;