iwl3945 performance loss during file transfer over network

[Terry]

Playing video over NFS or even an MP3 file effects wireless performance considerably after a few minutes use to the point where the MP3 or video will stutter and SSH session to local machines lag badly. During this time there is also some packet loss (about 10-15%). At one time I was downloading a 2GB file from the internet which was getting a good transfer rate and it dropped to a consistent low speed (from 1.1MB/s to 140KB/s) during this time the network appeared considerably laggy as when playing MP3 or playing video files.

I have already tried to enable debugging output for the module so I can provide more detailed info on what's going on but, I can't seem to get this to work. Can you advise what I can do to provide some debugging info so I can follow up with some more detailed information?

I have experienced this issue in Hardy too but not as excessive.

Description: Ubuntu intrepid (development branch)
Release: 8.10
policy linux-image-2.6.27-3-generic
linux-image-2.6.27-3-generic:
  Installed: 2.6.27-3.4
  Candidate: 2.6.27-3.4
  Version table:
 *** 2.6.27-3.4 0
        500 http://gb.archive.ubuntu.com intrepid/main Packages
        100 /var/lib/dpkg/status

[Terry (terry-kryogenic)]

BTW, I've used debug=0x43fff option but no debug output anywhere.

As nobody seems to know shall I just report this upstream?

[Leann Ogasawara (leannogasawara)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. Per the kernel team's bug policy, can you please attach the following information. Please be sure to attach each file as a separate attachment.

* dmesg > dmesg.log
* sudo lspci -vvnn > lspci-vvnn.log

For more information regarding the kernel team bug policy, please refer to https://wiki.ubuntu.com/KernelTeamBugPolicies . Thanks again and we appreciate your help and feedback.

[Terry (terry-kryogenic)]

Just to add that I am using the latest firmware available from intellinuxwireless.org (iwlwifi-3945-ucode-15.28.1.6) as there wasn't any available firmwares in Intrepid for my card at the time. My original hope was that the latest firmware would fix the issue but the problem still very much exists.

[macavity (bschroder)]

I have the same bug as of end of August-2008 but I am running Hardy 8.04.1 LTS.
iwl3945 can connect (although sometimes with great difficulties) to my WPA personal network. It works for about 2-3minutes and then it gets slower and slower until it stops working altogether.
I never had these problems before with Hardy or any previous versions.

Here is some data:

Thinkpad X60
NetworkManager: nm-applet 0.6.6

uname -a:
Linux rick-x60 2.6.24-19-generic #1 SMP Wed Aug 20 22:56:21 UTC 2008 i686 GNU/Linux

I installed linux-backports-2.6.24-19
I updated my iwl3945 firmware to iwlwifi-3945-ucode-15.28.1.6.tgz
from http://www.intellinuxwireless.org/?p=iwlwifi&n=downloads ,
extracted and copied it into /lib/firmware/ as well as updating the existing one in /lib/firmware/2.6.24-19-generic/

lsmod | grep iwl3945:
iwl3945 93940 0
iwlwifi_mac80211 219108 1 iwl3945
cfg80211 15112 1 iwlwifi_mac80211
led_class 6020 1 iwl3945

modinfo iwl3945:
filename: /lib/modules/2.6.24-19-generic/updates/wireless/iwlwifi/iwlwifi/compatible/iwl3945.ko
license: GPL
author: Copyright(c) 2003-2007 Intel Corporation
version: 1.2.25
description: Intel(R) PRO/Wireless 3945ABG/BG Network Connection driver for Linux
srcversion: FDE2E62843DE3ED112A50C3
alias: pci:v00008086d00004227sv*sd*bc*sc*i*
alias: pci:v00008086d00004222sv*sd*bc*sc*i*
depends: led-class,iwlwifi_mac80211
vermagic: 2.6.24-19-generic SMP mod_unload 586
parm: antenna:select antenna (1=Main, 2=Aux, default 0 [both]) (int)
parm: disable:manually disable the radio (default 0 [radio on]) (int)
parm: hwcrypto:using hardware crypto engine (default 0 [software])
 (int)
parm: debug:debug output mask (int)
parm: disable_hw_scan:disable hardware scanning (default 0) (int)
parm: queues_num:number of hw queues. (int)
parm: qos_enable:enable all QoS functionality (int)

syslogs: see attachment
lspci -vvnn: see attachment

[macavity (bschroder)]

Sorry, my previous syslog.txt attachment was generated when I tried Intrepid Alpha6.
Here is my syslog running Hardy.

[macavity (bschroder)]

I know that the wifi connections of my Thinkpad+Intel3945ABG(rev2) Network controller to my WPA Enterprise and WPA personal network worked flawlessly before mid Aug. 2008.
So I wiped my disk and reinstalled the original Hardy version 8.04 from scratch but I got the same problem.
I installed other distros, OpenSuse, Zenwalk etc. ... same problem. At first I usually get a list of available access points but then either I can't connect at all or I can connect but no data is coming through.

Could it be that the iwl3945 messes with the firmware as the e1000e driver does?
Something is fishy.

[Leann Ogasawara (leannogasawara)]

For those of you running Intrepid, just to see if it helps, you might want to try installing linux-backports-modules as it most recently pulled in an updated version of the compat-wireless stack:

https://edge.launchpad.net/ubuntu/+source/linux-backports-modules-2.6.27

linux-backports-modules-2.6.27 (2.6.27-7.3) intrepid; urgency=low

  [Tim Gardner]

  * Added iwlwifi firmware
  * Added the upstream compat-wireless-2.6 tree.
  * Updated compat-wireless to wireless-testing tag master-2008-10-14
  * Set CONFIG_WIRELESS_OLD_REGULATORY=y by default.

[Terry (terry-kryogenic)]

I've been testing backport-modules for about a week and the problem still very much exists.

[LumpyCustard (orangelumpycustard)]

What wireless encryption are you using? I had a similar problem and found (in another bug report somewhere) that moving from WPA to WEP is a workaround for the problem, which for me it was.

[Terry (terry-kryogenic)]

I'm using WPA, I'll try WEP and see what happens, although I won't use it even if it works.
I'll report back.

[Terry (terry-kryogenic)]

Sorry about the delay but I had to find the most convenient time when the network wasn't in use. I've tried testing WEP and I seem to get different behaviour. After some time transferring a 900MB avi via scp the I do not experience a loss of transfer speed but the WLAN connection drops off with no signal. I am sitting within a few feet of the AP.

From dmesg
[ 1371.260130] wlan0: No ProbeResp from current AP 00:1f:33:da:5e:68 - assume out of range

WLAN Comes back straight away after restarting networking. My network settings is manually configured.

[Terry (terry-kryogenic)]

My mistake, the connection drops using WPA too so I guess the behaviour is similar, Also other wireless machines are working fine (rt2500) and they are much further away so I do not think this is a router issue. I have also compiled and tested with the latest compat-wireless but the same issue remains.

I found this bug http://intellinuxwireless.org/bugzilla/show_bug.cgi?id=1593 tried the qos_enable workaround but no go and not sure if I should re-open the bug there or not.

[Launchpad Janitor (janitor)]

Per a decision made by the Ubuntu Kernel Team, bugs will longer be assigned to the ubuntu-kernel-team in Launchpad as part of the bug triage process. The ubuntu-kernel-team is being unassigned from this bug report. Refer to https://wiki.ubuntu.com/KernelTeamBugPolicies for more information. Thanks.

[Jeremy Foshee (jeremyfoshee)]

This bug report was marked as Triaged a while ago but has not had any updated comments for quite some time. Please let us know if this issue remains in the current Ubuntu release, http://www.ubuntu.com/getubuntu/download . If the issue remains, click on the current status under the Status column and change the status back to "New". Thanks.

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[Brad Figg (brad-figg)]

This bug was filed against a series that is no longer supported and so is being marked as Won't Fix. If this issue still exists in a supported series, please file a new bug.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.