Author Topic: Dell e6400 intel 5100 wifi random disconnect  (Read 2042 times)

Cytochromec

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Dell e6400 intel 5100 wifi random disconnect
« on: May 10, 2012, 11:30:37 AM »
We have some Dell e6400 (14 inch laptops) that are working really well on Ubermix until randomly a handful of them (3-10) in a class will disconnect from wifi and never reconnect. We have tried toggling the hardware switch and disabling and re-enabling networking from the Network Manager applet and they won't get back on. If the computer is restarted they connect again just fine. Some periods there are no issues.

Any ideas on how to kick the wireless card back into action without a restart?
Or any driver updates we could try to provide more consistent wifi connectivity?

jnetman1

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Re: Dell e6400 intel 5100 wifi random disconnect
« Reply #1 on: May 10, 2012, 11:32:20 AM »
Do an lshw -C network on one of the problem children and let me know what it says the wireless card is.

Cytochromec

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Re: Dell e6400 intel 5100 wifi random disconnect
« Reply #2 on: May 10, 2012, 03:57:19 PM »
*-network
       description: Wireless interface
       product: WiFi Link 5100
       vendor: Intel Corporation
       physical id: 0
       bus info: pci@0000:0c:00.0
       logical name: wlan4
       version: 00
       serial: 00:22:fb:3e:2a:76
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
       configuration: broadcast=yes driver=iwlagn driverversion=3.0.0-12-generic firmware=8.83.5.1 build 33692 ip=172.16.203.163 latency=0 link=yes multicast=yes wireless=IEEE 802.11abgn
       resources: irq:46 memory:f69fe000-f69fffff

I got to test a computer that wasn't reconnecting and I ran:
sudo modprobe -r iwlagn
sudo modprobe iwlagn

This kicked the wifi back to connecting. I have also been reading that perhaps disabling N networking helps this card work better. Here are possible instructions, but I haven't tried that yet.

    Press Ctrl + Alt + T. Type in this command: sudo gedit /etc/modprobe.d/intel_11n_disable.conf
    Paste this into the gedit window that opens: options iwlagn 11n_disable=1
    Save, and close gedit. When back at the prompt type sudo update-initramfs -u.
    Run sudo modprobe -r iwlagn && sudo modprobe iwlagn.
   
How can I run the disable N as a script and have to push out to the existing 60  (using the network autostart script)?
Or how can Iuse the network autostart script to place a FixMyWireless.sh file that would be executable to run the modprobe commands on each computer (and maybe even place a link on favorites to run the script in terminal).

Of course if you have other ideas, I would love to hear it!

jnetman1

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Re: Dell e6400 intel 5100 wifi random disconnect
« Reply #3 on: May 10, 2012, 04:14:52 PM »
I've seen something like that on other older Dells. A driver update might fix it. Try the following:

  • Go to http://linuxwireless.org/en/users/Download and get the latest bleeding-edge
  • Open a terminal (ctrl-alt-t) and tar -xjf Downloads/compat*
  • cd compat*
  • ./scripts/driver-select iwlagn
  • make && sudo make install
  • sudo depmod -a
  • sudo reboot

jnetman1

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Re: Dell e6400 intel 5100 wifi random disconnect
« Reply #4 on: May 10, 2012, 04:23:51 PM »
Scratch that - looks like the driver is no longer part of compat-wireless. Looks like the issue might have been fixed upstream. Just out of curiosity, have you tried 1.0 alpha on it? It has a very new kernel so it should have a newer driver.

Cytochromec

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Re: Dell e6400 intel 5100 wifi random disconnect
« Reply #5 on: May 10, 2012, 04:57:42 PM »
I haven't tried alpha 1, but would prefer to be able to avoid a reimage of the 60 if possible, because the problem is very rare and intermittent, so it is difficult to know if the change fixes it.