Comment 105 for bug 1574347

Ubuntu 16.04 on dell E6430, after upgrade:

- after suspend/resume sometimes the network manager cannot connect (but it tries: it keeps associating/de-associating) [before upgrade, the wifi was broken at this stage, cf below]
dmesg:
[101381.710749] wlan0: authenticate with 42:01:40:59:9f:3c
[101381.712600] wlan0: send auth to 42:01:40:59:9f:3c (try 1/3)
[101381.714512] wlan0: authenticated
[101381.716173] wlan0: associate with 42:01:40:59:9f:3c (try 1/3)
[101381.726242] wlan0: RX AssocResp from 42:01:40:59:9f:3c (capab=0x411 status=0 aid=4)
[101381.728513] wlan0: associated
[101388.076989] wlan0: deauthenticated from 42:01:40:59:9f:3c (Reason: 15=4WAY_HANDSHAKE_TIMEOUT)
[101388.104508] cfg80211: World regulatory domain updated:
[101388.104511] cfg80211: DFS Master region: unset
[101388.104512] cfg80211: (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp), (dfs_cac_time)

- if I deactivate and then reactivate the wifi, then it reverts to the old bug (where there is only one network available and nothing happens). sudo service network-manager restart repairs everything...
The bug is still at this point:
[101418.822530] IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
[101418.869145] IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
[101423.443499] e1000e: eth0 NIC Link is Down
[101426.202627] IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
[101426.202873] iwlwifi 0000:03:00.0: L1 Enabled - LTR Disabled
[101426.210391] iwlwifi 0000:03:00.0: L1 Enabled - LTR Disabled
[101426.210491] iwlwifi 0000:03:00.0: Radio type=0x0-0x3-0x1
[101426.434605] iwlwifi 0000:03:00.0: L1 Enabled - LTR Disabled
[101426.442165] iwlwifi 0000:03:00.0: L1 Enabled - LTR Disabled
[101426.442267] iwlwifi 0000:03:00.0: Radio type=0x0-0x3-0x1
a problem with the /dev/something, no?

strange...
hope this can be repaired soon. But also in the 14.04 distrib it was sometimes necessary to deactivate/restart the network manager to catch back the signal after resume...
good luck, thanks