wifi packet loss on intel Centrino Wireless-N 1000

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Did this just start happening after a recent update, or has it always happened on Raring?

Also, would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v3.9 kernel[0]. You will need to install both the linux-image and linux-image-extra .deb packages.

If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

If you are unable to test the mainline kernel, for example it will not boot, please add the tag: 'kernel-unable-to-test-upstream'.
Once testing of the upstream kernel is complete, please mark this bug as "Confirmed".

Thanks in advance.

[0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.9-rc6-raring/

I will try that kernel.

I don't know how long it's been happening. Unfortunately bug 1157114 means I rarely take the laptop out of the docking station, so it's mostly on a wired network.

wpasupplicant 2.0 from a PPA pointed out at bug #1099755 might be relevant. That's apparently related to connection drops with specific access points / environments.

Tested wpasupplicant 2.0 from the PPA Timo suggested using the stock raring kernel 3.8.0-17 but unfortunately it made no difference.

Also tried upstream 3.9 as requested and that too makes no difference.

I should point out I have two access points at opposite ends of the house, with the same ESSID. The one nearest my laptop right now is the only one it can see. It's a netgear wndr3700 running dd-wrt. The other one is the same model but running openwrt.

The fact remains a macbook pro sat next to it maintained a solid connection while testing, so I don't think there's anything wrong with the access points. I also never had this happen on 12.04 before upgrading.

I'd like to perform a bisect to figure out what commit caused this regression. It would be very helpful to know the earliest kernel where the issue started happening as well as the latest kernel that did not have this issue.

Can you test the following kernels and report back? We are looking for the first kernel version that exhibits this bug:

v3.6 final: http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.6-quantal/
v3.7 final: http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.7-raring/
v3.8-rc1: http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.8-rc1-raring/

You don't have to test every kernel, just up until the kernel that first has this bug.

One thing to note, you will need to install both the linux-image and linux-image-extra .deb packages.

Tested those 3 kernels and unfortunately the same problem happens on all of them. Results attached.

Incidentally while booted to 3.8.0-030800rc1-generic my disk became full due to bug 811604 with /var/log/uvcdynctrl-udev.log spammed up to 55GB...

3.5.0-23-generic (Ubuntu 12.04.2 live USB) works fine. Small amount of packet loss compared to previous kernel attempts.

                            My traceroute [v0.80]
ubuntu (0.0.0.0) Sat Apr 13 22:18:46 2013
Keys: Help Display mode Restart statistics Order of fields quit
                                       Packets Pings
 Host Loss% Snt Last Avg Best Wrst StDev
 1. 192.168.1.1 11.3% 335 6.3 8.9 3.9 89.7 7.6
 2. cpc8-farn5-2-0-gw.6-2.cable.virg 11.6% 335 32.5 31.7 12.9 368.6 36.9
 3. glfd-core-2b-ae3-4033.network.vi 11.0% 335 27.0 28.7 12.5 175.9 22.7
 4. glfd-bb-1b-ae6-0.network.virginm 11.3% 335 25.7 23.4 12.3 152.8 13.9
 5. glfd-bb-1a-ae0-0.network.virginm 11.6% 335 19.8 29.0 11.8 150.0 22.9
 6. nrth-bb-1b-ae4-0.network.virginm 11.3% 335 26.9 27.3 15.6 109.8 12.9
 7. tele-ic-4-ae0-0.network.virginme 11.3% 335 30.0 33.1 18.2 163.1 19.6
 8. linx-gw-a.jump.net.uk 11.3% 335 22.0 30.6 17.8 193.0 17.5
 9. dunkel.bitfolk.com 11.3% 335 30.1 29.2 17.8 125.4 15.0
10. popey.com 11.3% 335 22.1 28.3 18.3 170.9 12.9

.. but still enough packet loss to drop an ssh connection annoyinging frequently.

Booted to a 12.04 (not .1 or .2) iso and spent ages connected to ssh (while installing to another USB stick) and didn't drop my ssh connection once.

So 3.2.0-23-generic seems okay.

After install finished, I booted back into Ubuntu 13.04 running kernel 3.9.0-030900rc6-generic and it dropped the ssh connection for a whole minute within a minute of me starting the session. Saw this in dmesg just at the point of the drop which may or may not be related.

Apr 14 00:29:47 deep-thought dnsmasq[1810]: reading /etc/resolv.conf
Apr 14 00:29:47 deep-thought dnsmasq[1692]: reading /etc/resolv.conf
Apr 14 00:29:47 deep-thought dnsmasq[1692]: using nameserver 127.0.1.1#53
Apr 14 00:29:47 deep-thought dnsmasq[1810]: using nameserver 127.0.1.1#53
Apr 14 00:29:47 deep-thought dnsmasq[1810]: using local addresses only for unqualified names
Apr 14 00:29:55 deep-thought NetworkManager[1324]: <warn> nl_recvmsgs() error: (-33) Dump inconsistency detected, interrupted

Back on raring, using kernel 3.2.0-030200-generic (because 3.2 was so good under precise) I still get the same connection drop. So I'm officially confused now.

Ok, Spent the day yesterday on wireless with 802.11n disabled by adding this to /etc/modprobe.d/iwlwifi.conf

options iwlwifi 11n_disable=1 led_mode=1 swcrypto=1

It didn't drop my ssh connection at all during that time.

Thanks for the update, Alan. It sounds like you are seeing this with the Precise kernel as well per comment #15. Do you think you had 11n disabled in the past when you didn't see this in Precise?

If I boot to a stock precise install (kernel 3.2) I do _not_ get this problem.

I don't recall ever having disabled wireless n.

In fact I just checked my backups of this machine and the oldest one I have is from September 2012, running precise 3.2.0-29-generic. There's no setting in /etc/modprobe.d/*.conf which relates to iwlwifi. I checked my IRC logs and it seems I put this router in back in August 2012, and it hasn't been changed since. So it certainly did work (and still does booted from a USB stick install of precise running 3.2) with no fiddling, today. As soon as I upgrade to 3.5 or above, it breaks wireless N.

Do you still get this issue if you run a 3.2 kernel on Raring, like mentioned in comment #15? If so, it might be a good test to try the Raring kernel on a Precise install. Do you have the option of putting Precise on this machine to perform this test? I would expect the bug to happen in this case if the bug is kernel related. If it does't, it could suggest an issue in another package, such as network-manager.

Ok. Booted into a precise install and ran 3.2 kernel (default from install) and it's fine. Also installed 3.8.0-18-generic kernel from raring (https://launchpad.net/ubuntu/+source/linux/3.8.0-18.28/+build/4486060) , and that seems fine too.

So that implies something other than the kernel has changed which breaks this?

What now? Individually update packages like wpasupplicant, network-manager?

Just to confirm, did you re-enable 11n for your tests?

To clarify I am seeing working fine on precise clean install with precise 3.2 kernel and raring 3.8 kernel. I have seen the issue on this same machine with an up to date precise install. So the theory is it regresses during the precise lifecycle. As I have not updated yet, it therefore follows that one of these packages breaks it:-

output from apt-get -s dist-upgrade:- http://paste.ubuntu.com/5711407/

I never disabled 11n on my precise usb install. Only on my raring ssd install.

The fact that the Raring kernel does not exhibit the bug when installed on Precise indicates an issue with a package other than the kernel. I've added the network-manager task. We probably want to have foundations review the bug to get their feedback.

NetworkManager doesn't push packets on wifi. Could you try to see what happens to the routing table when you can't reach things?

ip route

The only thing I can say is that this is is most likely not NetworkManager, which just establishes the connections. It definitely needs more investigation.

Alan, do you happen to have this laptop in Oakland this week?

Joseph, I do, yes. Feel free

Hi Alan,

Just curious if you had a chance to test any of the kernels we discussed in Oakland. If needed, I can provide a list of kernels to test.

It's probably also best to install the latest updates to confirm this bug still exists as well.

Status changed to 'Confirmed' because the bug affects multiple users.

I can confirm this bug. It's really quite annoying. For me it started with 3.2 kernel (if i recall correctly) and did not work on any kernel i tried after that.
I've tried with wireless N disabled and it does not disconnect that often, but still makes it a pain to use.
I've updated wifi firmware with last iwlwifi-1000-5.ucode from iwlwifi project.
Also tried to compile most recent iwlwifi drivers with no avail.

Currently i am running:
$ uname -a
Linux vault 3.10.0-031000-generic #201306301935 SMP Sun Jun 30 23:36:16 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux

Often i am unable to connect to my wireless router for like 10 minutes with this error (connecting with other devices or in windows is without any problem):
Jul 1 23:12:51 vault wpa_supplicant[1551]: Trying to authenticate with 64:70:02:ab:35:fe (SSID='UaE2' freq=2447 MHz)
Jul 1 23:12:51 vault kernel: [ 1477.246476] wlan0: authenticate with 64:70:02:ab:35:fe
Jul 1 23:12:51 vault kernel: [ 1477.257644] wlan0: direct probe to 64:70:02:ab:35:fe (try 1/3)
Jul 1 23:12:51 vault kernel: [ 1477.459277] wlan0: direct probe to 64:70:02:ab:35:fe (try 2/3)
Jul 1 23:12:52 vault kernel: [ 1477.663286] wlan0: direct probe to 64:70:02:ab:35:fe (try 3/3)
Jul 1 23:12:52 vault kernel: [ 1477.867215] wlan0: authentication with 64:70:02:ab:35:fe timed out

See attached dmesg output to see more info.
I'll be glad to test anything in order to get this fixed ;)

I am running ubuntu 12.04 with all latest updates and have intalled the daily build kernel: 3.10.0-031000-generic #201306301935 SMP Sun Jun 30 23:36:16 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
from kernel packages:
linux-headers-3.10.0-999_3.10.0-999.201307110431_all.deb
linux-headers-3.10.0-999-generic_3.10.0-999.201307110431_amd64.deb
linux-image-3.10.0-999-generic_3.10.0-999.201307110431_amd64.deb

I have also created and installed most recent versions of:
libnl-3.2.22
network-manager 0.9.8.2
wpasupplicant 2.0

But still get disconnects like this:

Jul 12 18:19:27 vault NetworkManager[1491]: <warn> nl_recvmsgs() error: (-33) Dump inconsistency detected, interrupted
Jul 12 18:25:29 vault NetworkManager[1491]: <warn> nl_recvmsgs() error: (-33) Dump inconsistency detected, interrupted
Jul 12 18:41:27 vault NetworkManager[1491]: <warn> nl_recvmsgs() error: (-33) Dump inconsistency detected, interrupted
Jul 12 19:10:56 vault nm-openvpn[11225]: read TCPv4_CLIENT []: No route to host (code=113)
Jul 12 19:11:26 vault kernel: [30858.358269] iwlwifi 0000:03:00.0: fail to flush all tx fifo queues Q 11
Jul 12 19:11:26 vault kernel: [30858.358281] iwlwifi 0000:03:00.0: Current SW read_ptr 13 write_ptr 19
Jul 12 19:11:26 vault kernel: [30858.358363] iwl data: 00000000: 00 e0 07 00 00 c0 03 00 00 00 00 00 00 00 00 00 ................
Jul 12 19:11:26 vault kernel: [30858.358396] iwlwifi 0000:03:00.0: FH TRBs(0) = 0x00000000
Jul 12 19:11:26 vault kernel: [30858.358431] iwlwifi 0000:03:00.0: FH TRBs(1) = 0xc010b012
Jul 12 19:11:26 vault kernel: [30858.358466] iwlwifi 0000:03:00.0: FH TRBs(2) = 0x8020100a
Jul 12 19:11:26 vault kernel: [30858.358501] iwlwifi 0000:03:00.0: FH TRBs(3) = 0x803000e5
Jul 12 19:11:26 vault kernel: [30858.358536] iwlwifi 0000:03:00.0: FH TRBs(4) = 0x00000000
Jul 12 19:11:26 vault kernel: [30858.358569] iwlwifi 0000:03:00.0: FH TRBs(5) = 0x00000000
Jul 12 19:11:26 vault kernel: [30858.358602] iwlwifi 0000:03:00.0: FH TRBs(6) = 0x00000000
Jul 12 19:11:26 vault kernel: [30858.358633] iwlwifi 0000:03:00.0: FH TRBs(7) = 0x00704034
Jul 12 19:11:26 vault kernel: [30858.358751] iwlwifi 0000:03:00.0: Q 0 is active and mapped to fifo 3 ra_tid 0x0000 [230,230]
Jul 12 19:11:26 vault kernel: [30858.358871] iwlwifi 0000:03:00.0: Q 1 is active and mapped to fifo 2 ra_tid 0x0000 [11,11]
Jul 12 19:11:26 vault kernel: [30858.358992] iwlwifi 0000:03:00.0: Q 2 is active and mapped to fifo 1 ra_tid 0x0000 [133,133]
Jul 12 19:11:26 vault kernel: [30858.359113] iwlwifi 0000:03:00.0: Q 3 is active and mapped to fifo 0 ra_tid 0x0000 [0,0]
Jul 12 19:11:26 vault kernel: [30858.359233] iwlwifi 0000:03:00.0: Q 4 is active and mapped to fifo 7 ra_tid 0x0000 [53,53]
Jul 12 19:11:26 vault kernel: [30858.359355] iwlwifi 0000:03:00.0: Q 5 is inactive and mapped to fifo 0 ra_tid 0x0000 [0,0]
Jul 12 19:11:26 vault kernel: [30858.359476] iwlwifi 0000:03:00.0: Q 6 is inactive and mapped to fifo 0 ra_tid 0x0000 [0,0]
Jul 12 19:11:26 vault kernel: [30858.359597] iwlwifi 0000:03:00.0: Q 7 is inactive and mapped to fifo 0 ra_tid 0x0000 [0,0]
Jul 12 19:11:26 vault kernel: [30858.359715] iwlwifi 0000:03:00.0: Q 8 is inactive and mapped to fifo 0 ra_tid 0x0000 [0,0]
Jul 12 19...

I have installed the laest 3.11 kernel (3.11.0-999-generic #201307150405 SMP Mon Jul 15 08:06:42 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux) and so far there were no connection drops.
However i see these errors in syslog when the connection "freezes or stalls" for a while (no idea if it's related or not, just thought it might be worth to check):

Jul 15 19:23:47 vault kernel: [ 6662.366799] pcieport 0000:00:03.0: AER: Corrected error received: id=0018
Jul 15 19:23:47 vault kernel: [ 6662.366811] pcieport 0000:00:03.0: PCIe Bus Error: severity=Corrected, type=Data Link Layer, id=0018(Transmitter ID)
Jul 15 19:23:47 vault kernel: [ 6662.366815] pcieport 0000:00:03.0: device [8086:d138] error status/mask=00001000/00002000
Jul 15 19:23:47 vault kernel: [ 6662.366819] pcieport 0000:00:03.0: [12] Replay Timer Timeout
Jul 15 20:17:01 vault CRON[26145]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Jul 15 21:06:45 vault kernel: [12840.118574] usb 2-1.4: USB disconnect, device number 3
Jul 15 21:06:45 vault kernel: [12840.389722] usb 2-1.4: new low-speed USB device number 4 using ehci-pci
Jul 15 21:06:45 vault kernel: [12840.488735] usb 2-1.4: New USB device found, idVendor=045e, idProduct=00cb
Jul 15 21:06:45 vault kernel: [12840.488744] usb 2-1.4: New USB device strings: Mfr=1, Product=2, SerialNumber=0
Jul 15 21:06:45 vault kernel: [12840.488750] usb 2-1.4: Product: Microsoft Basic Optical Mouse v2.0
Jul 15 21:06:45 vault kernel: [12840.488754] usb 2-1.4: Manufacturer: Microsoft
Jul 15 21:06:45 vault kernel: [12840.491968] input: Microsoft Microsoft Basic Optical Mouse v2.0 as /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4/2-1.4:1.0/input/input16
Jul 15 21:06:45 vault kernel: [12840.492543] hid-generic 0003:045E:00CB.0002: input,hidraw0: USB HID v1.11 Mouse [Microsoft Microsoft Basic Optical Mouse v2.0 ] on usb-0000:00:1d.0-1.4/input0
Jul 15 21:17:01 vault CRON[5314]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Jul 15 21:31:29 vault kernel: [14324.515282] pcieport 0000:00:03.0: AER: Corrected error received: id=0018
Jul 15 21:31:29 vault kernel: [14324.515294] pcieport 0000:00:03.0: PCIe Bus Error: severity=Corrected, type=Data Link Layer, id=0018(Transmitter ID)
Jul 15 21:31:29 vault kernel: [14324.515298] pcieport 0000:00:03.0: device [8086:d138] error status/mask=00001000/00002000
Jul 15 21:31:29 vault kernel: [14324.515301] pcieport 0000:00:03.0: [12] Replay Timer Timeout
Jul 15 21:42:32 vault kernel: [14987.581500] pcieport 0000:00:03.0: AER: Corrected error received: id=0018
Jul 15 21:42:32 vault kernel: [14987.581510] pcieport 0000:00:03.0: PCIe Bus Error: severity=Corrected, type=Data Link Layer, id=0018(Transmitter ID)
Jul 15 21:42:32 vault kernel: [14987.581513] pcieport 0000:00:03.0: device [8086:d138] error status/mask=00001000/00002000
Jul 15 21:42:32 vault kernel: [14987.581516] pcieport 0000:00:03.0: [12] Replay Timer Timeout
Jul 15 21:59:55 vault kernel: [16029.878777] usb 2-1.4: USB disconnect, device number 4
Jul 15 21:59:55 vault kernel: [16030.111632] usb 2-1.4: new low-speed USB device number 5 using ehci-pci
Jul 15 21:59:55 vault kernel: [16030.210361] usb 2-1.4: New USB de...

I had to downgrade to latest 3.10 kernel due to some other issues, but i managed to compile it with IWLWIFI_DEBUG enabled.
I've attached disconnect_debug.log containing log data from 2 disconnects (syslog entries and iw event -t entries).

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