Hi guys, not sure if this got sent because it was reported as too long. I clipped it, so hopefully it gets through this time.


On Fri, Nov 18, 2011 at 12:28 PM, Vijay Boyapati <vijayb@gmail.com> wrote:

Dear Ubuntu gurus, I'm having a problem with my wireless at home that I've never had before.


I know the problem is somehow related to Ubuntu's (I'm running Natty 11.04) interaction with my router (mac airport extreme) because:

- My laptop is dual boot with windows- On windows wireless works fine at home- On Ubuntu wireless works fine everywhere except home (coffee shops etc)
When I boot into Ubuntu wireless will work fine for a few minutes and then become increasingly flaky. I am not 100% sure, but I suspect the flakiness begins or is exacerbated when I ssh into a remote machine (just a theory, I could be wrong).




A friend who's a linux sysadmin suggested this when he saw the output of my dmesg (which I paste below):
"Definitely see some kernel debug stuff going on. It's probably a bug with the N protocol. Try disabling N as indicated here:*http://www.thinkwiki.org/wiki/Intel_Centrino_Wireless-N_1000






I think I had something like that happen once upon a time. This will scale you back to G speeds (54Mbps), but probably will be stable."







Any ideas or help on how to solve this? Diagnostics below
--------------------------------------------------------------


64 bytes from*sea09s01-in-f18.1e100.net*(173.194.33.18): icmp_req=145 ttl=55 time=13.9 ms


64 bytes from*sea09s01-in-f18.1e100.net*(173.194.33.18): icmp_req=146 ttl=55 time=11.5 ms


From menger.local (10.0.1.8) icmp_seq=186 Destination Host UnreachableFrom menger.local (10.0.1.8) icmp_seq=187 Destination Host Unreachable


64 bytes from*173.194.33.18: icmp_req=190 ttl=55 time=26.1 ms


64 bytes from*173.194.33.18: icmp_req=193 ttl=55 time=14.1 ms


^C64 bytes from*173.194.33.18: icmp_req=199 ttl=55 time=11.9 ms






---*google.com*ping statistics ---


199 packets transmitted, 138 received, +2 errors, 30% packet loss, time 245416msrtt min/avg/max/mdev = 8.765/12.457/57.745/4.468 ms, pipe 2


------------------------------------vijay@menger:~$ lspci


00:00.0 Host bridge: Intel Corporation 2nd Generation Core Processor Family DRAM Controller (rev 09)
00:01.0 PCI bridge: Intel Corporation 2nd Generation Core Processor Family PCI Express Root Port (rev 09)


00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09)


00:16.0 Communication controller: Intel Corporation 6 Series Chipset Family MEI Controller #1 (rev 04)
00:1a.0 USB Controller: Intel Corporation 6 Series Chipset Family USB Enhanced Host Controller #2 (rev 05)


00:1b.0 Audio device: Intel Corporation 6 Series Chipset Family High Definition Audio Controller (rev 05)


00:1c.0 PCI bridge: Intel Corporation 6 Series Chipset Family PCI Express Root Port 1 (rev b5)
00:1c.1 PCI bridge: Intel Corporation 6 Series Chipset Family PCI Express Root Port 2 (rev b5)
00:1c.2 PCI bridge: Intel Corporation 6 Series Chipset Family PCI Express Root Port 3 (rev b5)
00:1c.3 PCI bridge: Intel Corporation 6 Series Chipset Family PCI Express Root Port 4 (rev b5)
00:1d.0 USB Controller: Intel Corporation 6 Series Chipset Family USB Enhanced Host Controller #1 (rev 05)


00:1f.0 ISA bridge: Intel Corporation HM65 Express Chipset Family LPC Controller (rev 05)


00:1f.2 SATA controller: Intel Corporation 6 Series Chipset Family 6 port SATA AHCI Controller (rev 05)


00:1f.3 SMBus: Intel Corporation 6 Series Chipset Family SMBus Controller (rev 05)01:00.0 VGA compatible controller: ATI Technologies Inc NI Seymour [AMD Radeon HD 6470M]


07:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 06)


0d:00.0 Network controller: Intel Corporation Centrino Wireless-N 1000


13:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. Device 5209 (rev 01)19:00.0 USB Controller: NEC Corporation uPD720200 USB 3.0 Host Controller (rev 04)


----------------------------------------------------------------------------------------------------------------------


vijay@menger:~$ ping 10.0.1.1
PING 10.0.1.1 (10.0.1.1) 56(84) bytes of data.


From 10.0.1.8 icmp_seq=8 Destination Host UnreachableFrom 10.0.1.8 icmp_seq=9 Destination Host Unreachable


From 10.0.1.8 icmp_seq=10 Destination Host Unreachable


From 10.0.1.8 icmp_seq=11 Destination Host UnreachableFrom 10.0.1.8 icmp_seq=12 Destination Host Unreachable


From 10.0.1.8 icmp_seq=15 Destination Host Unreachable


^C--- 10.0.1.1 ping statistics ---


18 packets transmitted, 0 received, +6 errors, 100% packet loss, time 17027mspipe 3


vijay@menger:~$ ping 10.0.1.0
Do you want to ping broadcast? Then -b


vijay@menger:~$*


----------------------------------------------------------------------------------------------------------------------DMESG (clipped to tail):

[ 970.832882] WARNING: at /build/buildd/linux-2.6.38/net/sched/sch_generic.c:256 dev_watchdog+0x2a0/0x2b0()
[ 970.832887] Hardware name: HP Pavilion dv6 Notebook PC
[ 970.832892] NETDEV WATCHDOG: eth0 (r8169): transmit queue 0 timed out
[ 970.832896] Modules linked in: usbhid hid aesni_intel cryptd aes_x86_64 aes_generic parport_pc ppdev snd_hda_codec_hdmi snd_hda_codec_idt joydev binfmt_misc arc4 snd_hda_intel snd_hda_codec iwlagn snd_hwdep i915 snd_pcm snd_seq_midi snd_rawmidi iwlcore snd_seq_midi_event mac80211 snd_seq uvcvideo hp_wmi sparse_keymap videodev snd_timer psmouse drm_kms_helper v4l2_compat_ioctl32 fglrx(P) cfg80211 drm snd_seq_device snd serio_raw rts_pstor(C) i2c_algo_bit soundcore snd_page_alloc video hp_accel lis3lv02d input_polldev lp parport ahci xhci_hcd r8169 libahci
[ 970.832980] Pid: 0, comm: swapper Tainted: P C 2.6.38-8-generic #42-Ubuntu
[ 970.832985] Call Trace:
[ 970.832989] <IRQ> [<ffffffff81065cef>] ? warn_slowpath_common+0x7f/0xc0
[ 970.833009] [<ffffffff81065de6>] ? warn_slowpath_fmt+0x46/0x50
[ 970.833019] [<ffffffff814ef450>] ? dev_watchdog+0x2a0/0x2b0
[ 970.833031] [<ffffffff81013a85>] ? native_sched_clock+0x15/0x70
[ 970.833040] [<ffffffff81013ae9>] ? sched_clock+0x9/0x10
[ 970.833048] [<ffffffff8108ea9d>] ? sched_clock_cpu+0xbd/0x110
[ 970.833056] [<ffffffff814ef1b0>] ? dev_watchdog+0x0/0x2b0
[ 970.833067] [<ffffffff81074964>] ? call_timer_fn+0x44/0x130
[ 970.833075] [<ffffffff814ef1b0>] ? dev_watchdog+0x0/0x2b0
[ 970.833084] [<ffffffff81075fb4>] ? run_timer_softirq+0x134/0x280
[ 970.833093] [<ffffffff8102c85d>] ? lapic_next_event+0x1d/0x30
[ 970.833100] [<ffffffff8106d538>] ? __do_softirq+0xa8/0x1c0
[ 970.833111] [<ffffffff810983ef>] ? tick_program_event+0x1f/0x30
[ 970.833118] [<ffffffff8100cf1c>] ? call_softirq+0x1c/0x30
[ 970.833125] [<ffffffff8100ea45>] ? do_softirq+0x65/0xa0
[ 970.833132] [<ffffffff8106d755>] ? irq_exit+0x85/0x90
[ 970.833142] [<ffffffff815cafb0>] ? smp_apic_timer_interrupt+0x70/0x9b
[ 970.833150] [<ffffffff8100c9d3>] ? apic_timer_interrupt+0x13/0x20
[ 970.833154] <EOI> [<ffffffff81098310>] ? tick_dev_program_event+0x40/0x100
[ 970.833171] [<ffffffff8133685a>] ? intel_idle+0xca/0x120
[ 970.833178] [<ffffffff81336839>] ? intel_idle+0xa9/0x120
[ 970.833190] [<ffffffff814a3bda>] ? cpuidle_idle_call+0xaa/0x1b0
[ 970.833203] [<ffffffff8100a266>] ? cpu_idle+0xa6/0xf0
[ 970.833210] [<ffffffff815a9205>] ? rest_init+0x75/0x80
[ 970.833221] [<ffffffff81acac8b>] ? start_kernel+0x3f5/0x400
[ 970.833231] [<ffffffff81aca388>] ? x86_64_start_reservations+0x132/0x136
[ 970.833239] [<ffffffff81aca253>] ? zap_identity_mappings+0x3e/0x41
[ 970.833248] [<ffffffff81aca458>] ? x86_64_start_kernel+0xcc/0xdb
[ 970.833253] ---[ end trace 705b7b8584bf326e ]---
[ 970.873044] r8169 0000:07:00.0: eth0: link up




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Vijay Boyapati wrote:
> On Fri, Nov 18, 2011 at 12:28 PM, Vijay Boyapati <vijayb@gmail.com>
wrote:
> >> Dear Ubuntu gurus, I'm having a problem with my wireless at home
> >> that I've never had before.

> >> When I boot into Ubuntu wireless will work fine for a few minutes
> >> and then become increasingly flaky. I am not 100% sure, but I
> >> suspect the flakiness begins or is exacerbated when I ssh into a
> >> remote machine (just a theory, I could be wrong).
> >>
> >>
> >> A friend who's a linux sysadmin suggested this when he saw the
> >> output of my dmesg (which I paste below):
> >>
> >> "Definitely see some kernel debug stuff going on. It's probably a
> >> bug with the N protocol. Try disabling N as indicated here:
> >> http://www.thinkwiki.org/wiki/Intel_Centrino_Wireless-N_1000
> >>
> >> I think I had something like that happen once upon a time. This
> >> will scale you back to G speeds (54Mbps), but probably will be
> >> stable."

What was the result of your attempt to disable the N protocol according
to that suggestion? If it was still the same problem, you probably hit
another bug.

> >> [ 970.832882] WARNING: at
> >> /build/buildd/linux-2.6.38/net/sched/sch_generic.c:256
> >> dev_watchdog+0x2a0/0x2b0() [ 970.832887] Hardware name: HP
> >> Pavilion dv6 Notebook PC [ 970.832892] NETDEV WATCHDOG: eth0
> >> (r8169): transmit queue 0 timed out [ 970.832896] Modules linked
> >> in: usbhid hid aesni_intel cryptd aes_x86_64 aes_generic
> >> parport_pc ppdev snd_hda_codec_hdmi snd_hda_codec_idt joydev
> >> binfmt_misc arc4 snd_hda_intel snd_hda_codec iwlagn snd_hwdep
> >> i915 snd_pcm snd_seq_midi snd_rawmidi iwlcore snd_seq_midi_event
> >> mac80211 snd_seq uvcvideo hp_wmi sparse_keymap videodev snd_timer
> >> psmouse drm_kms_helper v4l2_compat_ioctl32 fglrx(P) cfg80211 drm
> >> snd_seq_device snd serio_raw rts_pstor(C) i2c_algo_bit soundcore
> >> snd_page_alloc video hp_accel lis3lv02d input_polldev lp parport
> >> ahci xhci_hcd r8169 libahci [ 970.832980] Pid: 0, comm: swapper
> >> Tainted: P C 2.6.38-8-generic #42-Ubuntu [ 970.832985]
> >> Call Trace:
> >> [ 970.832989] <IRQ> [<ffffffff81065cef>] ?
> >> warn_slowpath_common+0x7f/0xc0 [ 970.833009]
> >> [<ffffffff81065de6>] ? warn_slowpath_fmt+0x46/0x50 [ 970.833019]
> >> [<ffffffff814ef450>] ? dev_watchdog+0x2a0/0x2b0 [ 970.833031]
> >> [<ffffffff81013a85>] ? native_sched_clock+0x15/0x70 [
> >> 970.833040] [<ffffffff81013ae9>] ? sched_clock+0x9/0x10 [
> >> 970.833048] [<ffffffff8108ea9d>] ? sched_clock_cpu+0xbd/0x110 [
> >> 970.833056] [<ffffffff814ef1b0>] ? dev_watchdog+0x0/0x2b0 [
> >> 970.833067] [<ffffffff81074964>] ? call_timer_fn+0x44/0x130 [
> >> 970.833075] [<ffffffff814ef1b0>] ? dev_watchdog+0x0/0x2b0 [
> >> 970.833084] [<ffffffff81075fb4>] ? run_timer_softirq+0x134/0x280
> >> [ 970.833093] [<ffffffff8102c85d>] ? lapic_next_event+0x1d/0x30
> >> [ 970.833100] [<ffffffff8106d538>] ? __do_softirq+0xa8/0x1c0 [
> >> 970.833111] [<ffffffff810983ef>] ? tick_program_event+0x1f/0x30
> >> [ 970.833118] [<ffffffff8100cf1c>] ? call_softirq+0x1c/0x30 [
> >> 970.833125] [<ffffffff8100ea45>] ? do_softirq+0x65/0xa0 [
> >> 970.833132] [<ffffffff8106d755>] ? irq_exit+0x85/0x90 [
> >> 970.833142] [<ffffffff815cafb0>] ?
> >> smp_apic_timer_interrupt+0x70/0x9b [ 970.833150]
> >> [<ffffffff8100c9d3>] ? apic_timer_interrupt+0x13/0x20 [
> >> 970.833154] <EOI> [<ffffffff81098310>] ?
> >> tick_dev_program_event+0x40/0x100 [ 970.833171]
> >> [<ffffffff8133685a>] ? intel_idle+0xca/0x120 [ 970.833178]
> >> [<ffffffff81336839>] ? intel_idle+0xa9/0x120 [ 970.833190]
> >> [<ffffffff814a3bda>] ? cpuidle_idle_call+0xaa/0x1b0 [
> >> 970.833203] [<ffffffff8100a266>] ? cpu_idle+0xa6/0xf0 [
> >> 970.833210] [<ffffffff815a9205>] ? rest_init+0x75/0x80 [
> >> 970.833221] [<ffffffff81acac8b>] ? start_kernel+0x3f5/0x400 [
> >> 970.833231] [<ffffffff81aca388>] ?
> >> x86_64_start_reservations+0x132/0x136 [ 970.833239]
> >> [<ffffffff81aca253>] ? zap_identity_mappings+0x3e/0x41 [
> >> 970.833248] [<ffffffff81aca458>] ? x86_64_start_kernel+0xcc/0xdb
> >> [ 970.833253] ---[ end trace 705b7b8584bf326e ]---
> >> [ 970.873044] r8169 0000:07:00.0: eth0: link up

I'm not sure if this is related to your wireless. To me it looks more
like it is related to your eth0. You could report a bug againts the
kernel, see <https://wiki.ubuntu.com/KernelTeam/KernelTeamBugPolicies>.


Nils

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