Comment 2 for bug 763663

Same error here, Natty amd64.
I can see this error especially when I unplug the network cable.

[ 115.060011] ------------[ cut here ]------------
[ 115.060020] WARNING: at /build/buildd/linux-2.6.38/net/sched/sch_generic.c:256 dev_watchdog+0x2a0/0x2b0()
[ 115.060023] Hardware name: System Product Name
[ 115.060025] NETDEV WATCHDOG: eth0 (8139too): transmit queue 0 timed out
[ 115.060027] Modules linked in: binfmt_misc iptable_filter ip_tables x_tables snd_hda_codec_realtek nvidia(P) snd_hda_intel snd_hda_codec snd_hwdep snd_pcm snd_seq_midi snd_rawmidi snd_seq_midi_event ppdev snd_seq parport_pc snd_timer snd_seq_device asus_atk0110 psmouse snd serio_raw soundcore nv_tco i2c_nforce2 snd_page_alloc lp parport uvesafb ahci floppy firewire_ohci 8139too 8139cp libahci firewire_core crc_itu_t sata_nv pata_amd
[ 115.060061] Pid: 0, comm: swapper Tainted: P 2.6.38-8-generic #42-Ubuntu
[ 115.060064] Call Trace:
[ 115.060066] <IRQ> [<ffffffff81065cef>] ? warn_slowpath_common+0x7f/0xc0
[ 115.060074] [<ffffffff81065de6>] ? warn_slowpath_fmt+0x46/0x50
[ 115.060077] [<ffffffff814ef450>] ? dev_watchdog+0x2a0/0x2b0
[ 115.060082] [<ffffffff81080877>] ? __queue_work+0xf7/0x3d0
[ 115.060085] [<ffffffff8108ea88>] ? sched_clock_cpu+0xa8/0x110
[ 115.060088] [<ffffffff81080b50>] ? delayed_work_timer_fn+0x0/0x40
[ 115.060092] [<ffffffff814ef1b0>] ? dev_watchdog+0x0/0x2b0
[ 115.060095] [<ffffffff81074964>] ? call_timer_fn+0x44/0x130
[ 115.060099] [<ffffffff814ef1b0>] ? dev_watchdog+0x0/0x2b0
[ 115.060102] [<ffffffff81075fb4>] ? run_timer_softirq+0x134/0x280
[ 115.060106] [<ffffffff8102c85d>] ? lapic_next_event+0x1d/0x30
[ 115.060109] [<ffffffff8106d538>] ? __do_softirq+0xa8/0x1c0
[ 115.060113] [<ffffffff810983ef>] ? tick_program_event+0x1f/0x30
[ 115.060116] [<ffffffff8100cf1c>] ? call_softirq+0x1c/0x30
[ 115.060119] [<ffffffff8100ea45>] ? do_softirq+0x65/0xa0
[ 115.060122] [<ffffffff8106d755>] ? irq_exit+0x85/0x90
[ 115.060126] [<ffffffff815cafb0>] ? smp_apic_timer_interrupt+0x70/0x9b
[ 115.060129] [<ffffffff8100c9d3>] ? apic_timer_interrupt+0x13/0x20
[ 115.060131] <EOI> [<ffffffff81014a4d>] ? mwait_idle+0x8d/0x120
[ 115.060137] [<ffffffff815c6e8a>] ? atomic_notifier_call_chain+0x1a/0x20
[ 115.060141] [<ffffffff8100a266>] ? cpu_idle+0xa6/0xf0
[ 115.060145] [<ffffffff815a9205>] ? rest_init+0x75/0x80
[ 115.060149] [<ffffffff81acac8b>] ? start_kernel+0x3f5/0x400
[ 115.060153] [<ffffffff81aca388>] ? x86_64_start_reservations+0x132/0x136
[ 115.060156] [<ffffffff81aca253>] ? zap_identity_mappings+0x3e/0x41
[ 115.060159] [<ffffffff81aca458>] ? x86_64_start_kernel+0xcc/0xdb
[ 115.060162] ---[ end trace 54f641403b3a92e9 ]---