Kernel Bug Tracker – Bug 43103
Unable to connect to 5Ghz wireless using Intel 4965 a/b/g/n
Last modified: 2012-05-25 17:45:31 UTC
Created attachment 72913 [details]
Unable to connect to 5Ghz, 2.4Ghz working fine, older versions of Ubuntu working up to and including ubuntu 11.04, broken after this point. Tested in mainline build, same problem occurs.
Occasionally connects, but usually just keeps requesting password for the network. They've recommended I open as a kernel bug.
darren@darren-xps:~$ uname -r
Created attachment 72914 [details]
Let me know if you need any further info. Thanks.
The original distro bug
Is this regression (i.e. some older kernel is able to connect with 5GHz AP) ?
Ahh, I should read description more carefully. It is regression - ubuntu 11.04 worked, what kernel version is there?
(In reply to comment #5)
> Ahh, I should read description more carefully. It is regression - ubuntu 11.04
> worked, what kernel version is there?
Working fine on 11.04, same hardware, same router, same wlan.
darren@darren-XPS-M1530:~$ uname -r
Ok, so this is most likely regression between 2.6.38 and 2.6.39 where the driver split was done between iwlwifi and iwlegacy. Please install 2.6.39 and confirm that the things do not work there (if works on 2.6.39, please find two consecutive kernel versions where bug was introduced i.e 3.0 and 3.1). Then provide verbose logs on good and bad kernel, so I could compere what we do differently regarding device programming on that kernel in your environment. How to generate logs is described here:
2.6.39 - I lose wifi access altogether, would you still need the logs for this?
You mean that 2.6.39 works even worse than 3.4 ? Hmm, did you use latest -stable release i.e. 18.104.22.168 ?
My bad, I was using an RC. Working ok on 22.214.171.124, will carry on testing when I can to work out when the problem jumps in. Cheers.
Created attachment 72991 [details]
modprobe -r iwl4965 good (126.96.36.199)
connects to 5ghz ok.
Created attachment 72992 [details]
modprobe -r iwl4965 bad (3.0.0-0300)
Fails to connect to 5ghz, repeatedly requests password for WEP only, even though the encryption is WPA. WPA not an option in the dropdown for encryption type.
Logs does not include debug messages, there is:
> Apr 19 21:25:08 darren-XPS-M1530 kernel: [ 122.136672] iwl4965: Unknown parameter `debug'
You did not compile with CONFIG_IWLWIFI_LEGACY_DEBUG option (option name can be different i.e current kernel it is CONFIG_IWLEGACY_DEBUG). Also do not forgot to clean up logs (i.e. do "echo > /var/log/kernel") before module load.
Hi - current progress, I compiled 3.4 with the debug options and currently it is working and connecting to 5Ghz. I will update next time it fails to connect.
So kernel update must fix some (mac80211?) bug. I do not believe that compiling without CONFIG_IWLEGACY_DEBUG breaks thinks (or maybe, can you check?).
Ok, I'm closing this bug, if issue will repeat just reopen it.