Comment 5 for bug 1467069

Hi

I get the same disconnecting problem in 15.04, I had no problem in 14.10. But with different computers and wireless cards.

Lenovo T61p
Kernel Linux tpjohthe 3.19.0-21-generic #21-Ubuntu SMP Sun Jun 14 18:31:11 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
LANG=C lshw -C network
       description: Wireless interface
       product: PRO/Wireless 4965 AG or AGN [Kedron] Network Connection
       vendor: Intel Corporation
       physical id: 0
       bus info: pci@0000:03:00.0
       logical name: wlan0
       version: 61
       serial: 00:21:XX:XX:XX:XX
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
       configuration: broadcast=yes driver=iwl4965 driverversion=3.19.0-21-generic firmware=228.61.2.24 ip=192.168.0.X latency=0 link=yes multicast=yes wireless=IEEE 802.11abgn
       resources: irq:33 memory:df2fe000-df2fffff

Lenovo T61
LANG=C lshw -C network
  *-network
       description: Wireless interface
       product: PRO/Wireless 3945ABG [Golan] Network Connection
       vendor: Intel Corporation
       physical id: 0
       bus info: pci@0000:03:00.0
       logical name: wlan0
       version: 02
       serial: 00:1c:XX:XX:XX:XX
       width: 32 bits
       clock: 33MHz
       capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
       configuration: broadcast=yes driver=iwl3945 driverversion=3.19.0-21-generic firmware=15.32.2.9 ip=192.168.0.Xlatency=0 link=yes multicast=yes wireless=IEEE 802.11abg
       resources: irq:33 memory:df3ff000-df3fffff

syslog
Jul 2 09:56:25 tpjohthe wpa_supplicant[1010]: wlan0: WPA: Group rekeying completed with 00:26:XX:XX:XX:XX [GTK=CCMP]
Jul 2 10:47:53 tpjohthe wpa_supplicant[1010]: wlan0: CTRL-EVENT-DISCONNECTED bssid=00:26:XX:XX:XX:XX reason=4 locally_generated=1
Jul 2 10:47:53 tpjohthe NetworkManager[789]: <warn> Connection disconnected (reason -4)
Jul 2 10:47:53 tpjohthe kernel: [ 9066.873467] cfg80211: Calling CRDA to update world regulatory domain
Jul 2 10:47:53 tpjohthe NetworkManager[789]: <info> (wlan0): supplicant interface state: completed -> disconnected
Jul 2 10:47:53 tpjohthe kernel: [ 9066.880573] cfg80211: World regulatory domain updated:
Jul 2 10:47:53 tpjohthe kernel: [ 9066.880577] cfg80211: DFS Master region: unset
Jul 2 10:47:53 tpjohthe kernel: [ 9066.880580] cfg80211: (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp), (dfs_cac_time)
Jul 2 10:47:53 tpjohthe kernel: [ 9066.880584] cfg80211: (2402000 KHz - 2472000 KHz @ 40000 KHz), (300 mBi, 2000 mBm), (N/A)
Jul 2 10:47:53 tpjohthe kernel: [ 9066.880588] cfg80211: (2457000 KHz - 2482000 KHz @ 40000 KHz), (300 mBi, 2000 mBm), (N/A)
Jul 2 10:47:53 tpjohthe kernel: [ 9066.880591] cfg80211: (2474000 KHz - 2494000 KHz @ 20000 KHz), (300 mBi, 2000 mBm), (N/A)
Jul 2 10:47:53 tpjohthe kernel: [ 9066.880594] cfg80211: (5170000 KHz - 5250000 KHz @ 40000 KHz), (300 mBi, 2000 mBm), (N/A)
Jul 2 10:47:53 tpjohthe kernel: [ 9066.880597] cfg80211: (5735000 KHz - 5835000 KHz @ 40000 KHz), (300 mBi, 2000 mBm), (N/A)
Jul 2 10:47:53 tpjohthe kernel: [ 9066.880615] cfg80211: Calling CRDA for country: SE
Jul 2 10:47:53 tpjohthe kernel: [ 9066.883960] cfg80211: Regulatory domain changed to country: SE
Jul 2 10:47:53 tpjohthe kernel: [ 9066.883963] cfg80211: DFS Master region: ETSI
Jul 2 10:47:53 tpjohthe kernel: [ 9066.883965] cfg80211: (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp), (dfs_cac_time)
Jul 2 10:47:53 tpjohthe kernel: [ 9066.883969] cfg80211: (2402000 KHz - 2482000 KHz @ 40000 KHz), (N/A, 2000 mBm), (N/A)
Jul 2 10:47:53 tpjohthe kernel: [ 9066.883973] cfg80211: (5170000 KHz - 5250000 KHz @ 40000 KHz), (N/A, 2000 mBm), (N/A)
Jul 2 10:47:53 tpjohthe kernel: [ 9066.883976] cfg80211: (5250000 KHz - 5330000 KHz @ 40000 KHz), (N/A, 2000 mBm), (0 s)
Jul 2 10:47:53 tpjohthe kernel: [ 9066.883979] cfg80211: (5490000 KHz - 5710000 KHz @ 40000 KHz), (N/A, 2700 mBm), (0 s)
Jul 2 10:47:53 tpjohthe kernel: [ 9066.883982] cfg80211: (57240000 KHz - 65880000 KHz @ 2160000 KHz), (N/A, 4000 mBm), (N/A)
Jul 2 10:47:54 tpjohthe NetworkManager[789]: <info> (wlan0): supplicant interface state: disconnected -> scanning
Jul 2 10:48:09 tpjohthe NetworkManager[789]: <warn> (wlan0): link timed out.
Jul 2 10:48:09 tpjohthe NetworkManager[789]: <info> (wlan0): device state change: activated -> failed (reason 'ssid-not-found') [100 120 53]
Jul 2 10:48:09 tpjohthe NetworkManager[789]: <info> NetworkManager state is now CONNECTED_LOCAL
Jul 2 10:48:09 tpjohthe NetworkManager[789]: <info> NetworkManager state is now DISCONNECTED
Jul 2 10:48:09 tpjohthe whoopsie[826]: [10:48:09] offline
Jul 2 10:48:09 tpjohthe NetworkManager[789]: <warn> Activation (wlan0) failed for connection

When I restart with /etc/init.d/network-manager restart It is working again.

I will try a new kernel and see if it is working better..