[PATCH] Ensure IF_READY is unset when link is not ready

[Mitsuru Chinen <mitch@linux.vnet.ibm.com>]

Hi there,

On linux-2.6.21-rc2 or later, IPv6 link-local address is not assigned to
some kind of interfaces during system start-up. (I found this issue
occures with e100, e1000 and tg3.)

This issue comes from the change that inet6_dev is allocated when
NETDEV_REGISTER event occurs. The allocation code is at ipv6_add_dev()
in net/ipv6/addrinfo.c. At the code, IF_READY bit would be set when the
link is ready. The link readyness is verified by netif_caeeir_ok().
However as the drivers don't call netif_carrier_off() prior to calling
register_netdev(), netif_caeeir_ok() returns true in spite of the
actual link state.

Here's a work around patch. This make IF_READY unset when NETDEV_UP
event occurs and the link is not ready. This patch may not be an
fundamental fix. But I don't have any other idea now.

Signed-off-by: Mitsuru Chinen <mitch@linux.vnet.ibm.com>
---
 net/ipv6/addrconf.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index e16f1bb..1593cd1 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -2196,6 +2196,7 @@ static int addrconf_notify(struct notifi
 					"ADDRCONF(NETDEV_UP): %s: "
 					"link is not ready\n",
 					dev->name);
+				idev->if_flags &= ~IF_READY;
 				break;
 			}
 
-- 
1.4.3.4