Comment 0 for bug 1035889

Hossein Atashi (atashi.h) wrote :

I've had an intermittent system hard freeze problem for 2 years. Today I was finally able ro reproduce it.

I have a Dell Latitude E4300 laptop with Intel WiFi Link 5100 wireless adaptor. Whenever I switch to 11Mbps speed:

$ sudo iwconfig wlan0 rate 11M

causes a total system freeze from which I cannot recover even using the Magic SysRq+REISUB key sequence. This is especially a problem because I think (but have no evidence) automatic switching to this speed causes system freeze as well (which results in intermittent problems).

It is noteworthy that I can reproduce the same crash on a Lenovo ThinkPad X230 with an Intel Ultimate-N 6300 wireless adaptor. Switching to 11Mbps results in a total system freeze on this laptop as well. I think the only related common module between these laptops is iwlwifi driver.

I don't know whether this depends on my connection too or not, but here is my connection information just in case:

$ sudo iwconfig
lo no wireless extensions.

wlan0 IEEE 802.11abgn ESSID:"XXXXXXXXXXX"
          Mode:Managed Frequency:2.437 GHz Access Point: XX:XX:XX:XX:XX:XX
          Bit Rate=21.7 Mb/s Tx-Power=15 dBm
          Retry long limit:7 RTS thr:off Fragment thr:off
          Encryption key:off
          Power Management:off
          Link Quality=51/70 Signal level=-59 dBm
          Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
          Tx excessive retries:597 Invalid misc:2117 Missed beacon:0

eth0 no wireless extensions.

In case there is any more information I can provide to help triangulate the problem further, let me know.