Bug 729405

Summary: Missing wifi (iwlagn) when at kernel 2.6.40-4.fc15.x86_64 - 11n_disable50
Product: [Fedora] Fedora Reporter: Joakim Hovlandsvåg <joakim.hovlandsvag>
Component: kernelAssignee: Kernel Maintainer List <kernel-maint>
Status: CLOSED NOTABUG QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: unspecified    
Version: 15CC: aquini, gansalmon, itamar, joakim.hovlandsvag, jonathan, kernel-maint, linville, madhu.chinakonda
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Hardware: x86_64   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
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Clone Of: Environment:
Last Closed: 2011-08-09 19:19:35 UTC Type: ---
Regression: --- Mount Type: ---
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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What dmesg is saying (if of any help) none

Description Joakim Hovlandsvåg 2011-08-09 18:18:40 UTC 
User-Agent:       Mozilla/5.0 (X11; Linux x86_64; rv:5.0) Gecko/20100101 Firefox/5.0

After upgrading to kernel 2.6.40-4.fc15.x86_64 the wifi is missing, and no wlan0 or anything similar exists in `ifconfig -a`. When starting up with the older kernel version (2.6.38.8-35.fc15.x86_64), the wifi is working ok.

The wired network is unaffected.

Reproducible: Always

Steps to Reproduce:
1. Upgrading the yum packages, so the latest kernel is added.
2. Reboot with kernel 2.6.40-4.fc15.x86_64 with existing wireless card.
Actual Results:  
The wireless card is not being set up, ie. it isn't reachable as e.g. 'wlan0'.


The laptop is an HP EliteBook 6930p, preupgraded from fedora14, and the network card is "Intel Corporation PRO/Wireless 5100 AGN [Shiloh]".

A suggestion for the problem is a complaint about a missing parameter in iwlagn:

dmesg is complaining about:

  iwlagn: Unknown parameter `11n_disable50'

while /etc/modprobe.d/iwlwifi.conf says:

  options iwlagn 11n_disable50=1 11n_disable=1


$ modinfo iwlagn | grep parm
parm:           led_mode:0=system default, 1=On(RF On)/Off(RF Off), 2=blinking (int)
parm:           no_sleep_autoadjust:don't automatically adjust sleep level according to maximum network latency (bool)
parm:           bt_coex_active:enable wifi/bluetooth co-exist (bool)
parm:           debug:debug output mask (uint)
parm:           swcrypto:using crypto in software (default 0 [hardware]) (int)
parm:           queues_num:number of hw queues. (int)
parm:           11n_disable:disable 11n functionality (int)
parm:           amsdu_size_8K:enable 8K amsdu size (int)
parm:           fw_restart:restart firmware in case of error (int)
parm:           ucode_alternative:specify ucode alternative to use from ucode file (int)
parm:           antenna_coupling:specify antenna coupling in dB (defualt: 0 dB) (int)
parm:           bt_ch_inhibition:Disable BT channel inhibition (default: enable) (bool)
parm:           plcp_check:Check plcp health (default: 1 [enabled]) (bool)
parm:           ack_check:Check ack health (default: 0 [disabled]) (bool)

This was just something I found out by following the examples in http://forums.opensuse.org/english/get-technical-help-here/wireless/448350-no-wifi-after-kernel-update.html, so it might not be the problem.
Comment 1 Joakim Hovlandsvåg 2011-08-09 18:22:44 UTC 
Created attachment 517459 [details]
What dmesg is saying (if of any help)
Comment 2 John W. Linville 2011-08-09 19:19:35 UTC 
Edit /etc/modprobe.d/iwlwifi.conf and make it look like this:

   options iwlagn 11n_disable=1

You might just remove that file instead, if 802.11n support is working OK for you now.

As far as I know, /etc/modprobe.d/iwlwifi.conf is not a file from a Fedora package.  Use 'rpm -qf /etc/modprobe.d/iwlwifi.conf' to see if I am wrong about that.

I'm going to close that on the assumption that the above resolves the issue for you.