Re: eth0 carrier wrongly seen on

[Dan Williams <dcbw redhat com>]

On Fri, 2009-01-16 at 21:20 +0100, Sébastien Mazy wrote:
> Hello,
> 
> I updated today from Linux 2.6.27.8 to 2.6.28. Since this update, NM
> 0.7.0 has seen my eth0 (driven by e1000e kernel module) carrier as on,
> even where there was no cable plugged.
> 
> What do you think? Is it a e1000e bug or does NM need changes to work
> properly with Linux 2.6.28?
> 
> 'cat /sys/class/net/eth0/carrier' --> '0' after the 'connection' on eth0
> is achieved and no cable was plugged in.

Carrier detection is driven by netlink events, so the issue could be in
a number of places.  To do top-level debugging, when you plug a cable in
and unplug it again, does anything happen in the log?  Failing that,
we'll need to make a netlink carrier test tool to show what's happening
on netlink and see if the kernel/driver is lying to us or not delivering
events.

dan


> Here is the relevant log part:
> 
> NetworkManager: <info>  starting...
> NetworkManager: <WARN>  nm_generic_enable_loopback(): error -17 returned from rtnl_addr_add(): Sucess
> NetworkManager: <info>  eth0: driver is 'e1000e'.
> NetworkManager: <info>  Found new Ethernet device 'eth0'.
> NetworkManager: <info>  (eth0): exported as /org/freedesktop/Hal/devices/net_00_1a_6b_67_da_70
> NetworkManager: <info>  wlan0: driver is 'iwlagn'.
> NetworkManager: <info>  wlan0: driver supports SSID scans (scan_capa 0x01).
> NetworkManager: <info>  Found new 802.11 WiFi device 'wlan0'.
> NetworkManager: <info>  (wlan0): exported as /org/freedesktop/Hal/devices/net_00_13_e8_29_46_e3
> NetworkManager: <info>  Trying to start the supplicant...
> NetworkManager: <info>  Trying to start the system settings daemon...
> NetworkManager: <info>  (wlan0): supplicant manager state:  down -> idle
> nm-system-settings: Loaded plugin keyfile: (c) 2007 - 2008 Red Hat, Inc.  To report bugs please use the NetworkManager mailing list.
> NetworkManager: <info>  (eth0): device state change: 1 -> 2
> NetworkManager: <info>  (eth0): bringing up device.
> ADDRCONF(NETDEV_UP): eth0: link is not ready
> NetworkManager: <info>  (eth0): preparing device.
> NetworkManager: <info>  (eth0): deactivating device (reason: 2).
> NetworkManager: <info>  (eth0): carrier now ON (device state 2)
> NetworkManager: <info>  (eth0): device state change: 2 -> 3
> NetworkManager: <info>  (wlan0): device state change: 1 -> 2
> NetworkManager: <info>  (wlan0): bringing up device.
> iwlagn 0000:03:00.0: PCI INT A -> GSI 17 (level, low) -> IRQ 17
> iwlagn 0000:03:00.0: firmware: requesting iwlwifi-4965-2.ucode
> Registered led device: iwl-phy0:radio
> Registered led device: iwl-phy0:assoc
> Registered led device: iwl-phy0:RX
> Registered led device: iwl-phy0:TX
> ADDRCONF(NETDEV_UP): wlan0: link is not ready
> NetworkManager: <info>  (wlan0): preparing device.
> NetworkManager: <info>  (wlan0): deactivating device (reason: 2).
> NetworkManager: <info>  Activation (eth0) starting connection 'home static'
> NetworkManager: <info>  (eth0): device state change: 3 -> 4
> 
> and so on until eth0 and wlan0 are configured and eth0 is chosen as
> default route:
> 
> NetworkManager: <info>  Policy set 'home static' (eth0) as default for routing and DNS.
> 
> 
> Cheers,
>