Ad Hoc wlan (hotspot) is completely broken for linux-image-3.2.0-27-generic at least on my particular hardware. The bug report says -24 because ubuntu-bug didn't allow me to edit that and I'm running -24 as a workaround. No problem there. I tried linux-image-3.2.0-26-generic to pinpoint the bug's appearance. It worked.
Adapter is 03:00.0 Network controller: Intel Corporation Centrino Advanced-N 6205 (rev 34)
Snippet of syslog representative of the problem, under -27:
Jul 27 22:47:31 t420s-4 wpa_supplicant[1752]: Trying to associate with SSID 't420s-4'
Jul 27 22:47:31 t420s-4 kernel: [ 92.126605] iwlwifi 0000:03:00.0: L1 Enabled; Disabling L0S
Jul 27 22:47:31 t420s-4 kernel: [ 92.126821] iwlwifi 0000:03:00.0: Radio type=0x1-0x2-0x0
Jul 27 22:47:31 t420s-4 wpa_supplicant[1752]: nl80211: Failed to set interface into IBSS mode
Jul 27 22:47:31 t420s-4 wpa_supplicant[1752]: Association request to the driver failed
Jul 27 22:47:31 t420s-4 kernel: [ 92.250848] ADDRCONF(NETDEV_UP): wlan0: link is not ready
Jul 27 22:47:41 t420s-4 wpa_supplicant[1752]: Authentication with 00:00:00:00:00:00 timed out.
ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: linux-image-3.2.0-24-generic 3.2.0-24.39
ProcVersionSignature: Ubuntu 3.2.0-24.39-generic 3.2.16
Uname: Linux 3.2.0-24-generic x86_64
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.24.
ApportVersion: 2.0.1-0ubuntu11
Architecture: amd64
ArecordDevices:
**** List of CAPTURE Hardware Devices ****
card 0: PCH [HDA Intel PCH], device 0: CONEXANT Analog [CONEXANT Analog]
Subdevices: 1/1
Subdevice #0: subdevice #0
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/controlC0: mjrauhal 2794 F.... pulseaudio
CRDA: Error: [Errno 2] No such file or directory
Card0.Amixer.info:
Card hw:0 'PCH'/'HDA Intel PCH at 0xf1620000 irq 50'
Mixer name : 'Intel CougarPoint HDMI'
Components : 'HDA:14f1506e,17aa21d2,00100002 HDA:80862805,80860101,00100000'
Controls : 26
Simple ctrls : 8
Card29.Amixer.info:
Card hw:29 'ThinkPadEC'/'ThinkPad Console Audio Control at EC reg 0x30, fw unknown'
Mixer name : 'ThinkPad EC (unknown)'
Components : ''
Controls : 1
Simple ctrls : 1
Card29.Amixer.values:
Simple mixer control 'Console',0
Capabilities: pswitch pswitch-joined penum
Playback channels: Mono
Mono: Playback [on]
CurrentDmesg:
Error: command ['sh', '-c', 'dmesg | comm -13 --nocheck-order /var/log/dmesg -'] failed with exit code 1: comm: /var/log/dmesg: Permission denied
dmesg: write failed: Broken pipe
Date: Fri Jul 27 23:31:57 2012
MachineType: LENOVO 4173L7G
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-3.2.0-24-generic root=/dev/mapper/t420s--4-root ro quiet splash vt.handoff=7
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
WifiSyslog:
dmi.bios.date: 09/14/2011
dmi.bios.vendor: LENOVO
dmi.bios.version: 8CET49WW (1.29 )
dmi.board.asset.tag: Not Available
dmi.board.name: 4173L7G
dmi.board.vendor: LENOVO
dmi.board.version: Not Available
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvr8CET49WW(1.29):bd09/14/2011:svnLENOVO:pn4173L7G:pvrThinkPadT420s:rvnLENOVO:rn4173L7G:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 4173L7G
dmi.product.version: ThinkPad T420s
dmi.sys.vendor: LENOVO
This bug is missing log files that will aid in diagnosing the problem. From a terminal window please run:
apport-collect 1030123
and then change the status of the bug to 'Confirmed'.
If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.
This change has been made by an automated script, maintained by the Ubuntu Kernel Team.