I suspended my laptop [closed the lid] and when I reopened it wifi would not connect. Logout and login did not fix the problem.
My wifi name is not broadcast
The hidden name had all the data included
I had just performed apt update & upgrade
uname -a
Linux Dell-1749 4.4.0-15-generic #31-Ubuntu SMP Fri Mar 18 19:08:31 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
Reboot was necessary to re-establish wifi.
@wolfman Thanks for the quick reply.
As part of my investigation I decided to simply close the lid after my reboot. Upon re-opening the lid wifi was restored as it usually is. I’ll investigate logs if this happens again [my gut tells me this was a one off]
After numerous lid closes and re-opens the bulit in wifi on this Dell laptop suspend and resume works perfectly
I've had problems in 15.10 with Wi-Fi causing problems after suspend, but not always. Restarting the network service seems to temporarily restore functionality for me:
sudo service NetworkManager restart
or
sudo service network-manager restart
Since it was USB, I had to physically remove it and plug it in before it behaved again. You may be able to do the same next time by pressing a physical hardware switch for Wi-Fi, if there is one.
Well I was mistaken about this being a one off. Today at 11:51 I closed my laptop to run some errands; when I opened the lid at 16:15 the wireless connection failed to re-establish. When I examined the network connection icon I noticed that my hidden network was identified, but reconnect was greyed out.Since I didn't have this thread open I decided to attempt to establish a new connection to the same hidden network - this was successful.
Discrepancies noted:
I'm not exactly certain how to proceed from my investigation:
lspci |grep Network
08:00.0 Network controller: Broadcom Corporation BCM43224 802.11a/b/g/n (rev 01)
uname -a
Linux Dell-1749 4.4.0-15-generic #31-Ubuntu SMP Fri Mar 18 19:08:31 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
syslog entries:
Mar 26 11:51:54 Dell-1749 systemd[1]: Starting Suspend...
Mar 26 11:51:54 Dell-1749 systemd-sleep[10509]: Selected interface 'wlp8s0'
Mar 26 11:51:54 Dell-1749 systemd-sleep[10509]: OK
Mar 26 11:51:54 Dell-1749 systemd-sleep[10509]: Suspending system...
Mar 26 16:15:57 Dell-1749 kernel: [ 6609.366590] PM: Syncing filesystems ... done.
Mar 26 16:15:57 Dell-1749 kernel: [ 6609.486018] PM: Preparing system for sleep (mem)
Mar 26 16:15:57 Dell-1749 kernel: [ 6609.486266] Freezing user space processes ...(elapsed 0.002 seconds) done.
Mar 26 16:15:57 Dell-1749 kernel: [ 6609.488384] Freezing remaining freezable tasks... (elapsed 0.001 seconds) done.
Mar 26 16:15:57 Dell-1749 kernel: [ 6609.489620] PM: Suspending system (mem)
Mar 26 16:15:57 Dell-1749 kernel: [ 6609.489682] Suspending console(s) (useno_console_suspend to debug)
Mar 26 16:15:57 Dell-1749 kernel: [ 6609.491076] sd 0:0:0:0: [sda] Synchronizing SCSI cache
Mar 26 16:15:57 Dell-1749 kernel: [ 6609.592458] sd 0:0:0:0: [sda] Stopping disk
Mar 26 16:15:57 Dell-1749 kernel: [ 6610.207139] PM: suspend of devices complete after 717.274 msecs
Mar 26 16:15:57 Dell-1749 kernel: [ 6610.223174] PM: late suspend of devices complete after 16.029 msecs
Mar 26 16:15:57 Dell-1749 kernel: [ 6610.251020] ehci-pci 0000:00:1d.0: System wakeup enabled by ACPI
Mar 26 16:15:57 Dell-1749 kernel: [ 6610.251031] ehci-pci 0000:00:1a.0: System wakeup enabled by ACPI
Mar 26 16:15:57 Dell-1749 kernel: [ 6610.267027] PM: noirq suspend of devices complete after 43.847 msecs
Mar 26 16:15:57 Dell-1749 kernel: [ 6610.267238] ACPI: Preparing to enter system sleep state S3
Mar 26 16:15:57 Dell-1749 kernel: [ 6610.355058] ACPI : EC: EC stopped
kernlog entries:
Mar 26 11:51:52 Dell-1749 kernel: [ 6606.485564] ata1.00: configured for UDMA/100
Mar 26 11:51:52 Dell-1749 kernel: [ 6606.648804] IPv6: ADDRCONF(NETDEV_UP): enp32s0:link is not ready
Mar 26 11:51:52 Dell-1749 kernel: [ 6606.712586] r8169 0000:20:00.0 enp32s0: link down
Mar 26 11:51:52 Dell-1749 kernel: [ 6606.712711] IPv6: ADDRCONF(NETDEV_UP): enp32s0:link is not ready
Mar 26 11:51:52 Dell-1749 kernel: [ 6606.715156] IPv6: ADDRCONF(NETDEV_UP): wlp8s0:link is not ready
Mar 26 11:51:52 Dell-1749 kernel: [ 6606.770087] ERROR @wl_cfg80211_scan : WLC_SCAN error (-22)
Mar 26 16:15:57 Dell-1749 kernel: [ 6609.366590] PM: Syncing filesystems ... done.
Mar 26 16:15:57 Dell-1749 kernel: [ 6609.486018] PM: Preparing system for sleep (mem)
Mar 26 16:15:57 Dell-1749 kernel: [ 6609.486266] Freezing user space processes ...(elapsed 0.002 seconds) done.
Mar 26 16:15:57 Dell-1749 kernel: [ 6609.488384] Freezing remaining freezable tasks... (elapsed 0.001 seconds) done.
Mar 26 16:15:57 Dell-1749 kernel: [ 6609.489620] PM: Suspending system (mem)
Mar 26 16:15:57 Dell-1749 kernel: [ 6609.489682] Suspending console(s) (use no_console_suspend to debug)
Mar 26 16:15:57 Dell-1749 kernel: [ 6609.491076] sd 0:0:0:0: [sda] Synchronizing SCSI cache
Mar 26 16:15:57 Dell-1749 kernel: [ 6609.592458] sd 0:0:0:0: [sda] Stopping disk
Mar 26 16:15:57 Dell-1749 kernel: [ 6610.207139] PM: suspend of devices complete after 717.274 msecs
Mar 26 16:15:57 Dell-1749 kernel: [ 6610.223174] PM: late suspend of devices complete after 16.029 msecs
authlog entries:
Mar 26 11:17:01 Dell-1749 CRON[25228]: pam_unix(cron:session): session opened for user root by (uid=0)
Mar 26 11:17:01 Dell-1749 CRON[25228]: pam_unix(cron:session): session closed for user root
Mar 26 11:51:43 Dell-1749 systemd-logind[807]: Lid closed.
Mar 26 11:51:50 Dell-1749 systemd-logind[807]: Lid opened.
Mar 26 11:51:50 Dell-1749 systemd-logind[807]: Operation 'sleep' finished.
Mar 26 11:51:51 Dell-1749 dbus[754]: [system] Rejected send message, 10 matched rules; type="method_return", sender=":1.29" (uid=0 pid=3252 comm="/usr/sbin/dnsmasq --no-resolv--keep-in-foreground") interface="(unset)" member="(unset)" error name="(unset)" requested_reply="0" destination=":1.9" (uid=0 pid=760 comm="/usr sbin/NetworkManager --no-daemon ")
Mar 26 11:51:54 Dell-1749 systemd-logind[807]: Lid closed.
Mar 26 16:15:57 Dell-1749 systemd-logind[807]: Lid opened.
Mar 26 16:15:57 Dell-1749 systemd-logind[807]: Operation 'sleep' finished.
Mar 26 16:17:01 Dell-1749 CRON[12577]: pam_unix(cron:session): session opened for user root by (uid=0)
Mar 26 16:17:01 Dell-1749 CRON[12577]: pam_unix(cron:session): session closed for user root
Mar 26 16:20:20 Dell-1749 dbus[754]: [system] Rejected send message, 10 matched rules; type="method_return", sender=":1.29" (uid=0 pid=3252 comm="/usr/sbin/dnsmasq --no-resolv--keep-in-foreground") interface="(unset)" member="(unset)" error name="(unset)" requested_reply="0" destination=":1.9" (uid=0 pid=760 comm="/usr/sbin/NetworkManager --no-daemon ")
TIA
Pete
Hi Pete,
do you have the open just to blank the screen instead of suspending or hibernation in the power management settings and have you checked there?. 
Control Centre > Hardware > Power manager.
Thanks @wolfman If I understood you correctly - when the laptop lid is closed the action selected is suspend [the same for AC and battery]]
I don’t see any selections available for open
I searched dconf settings org > mate > power and didn’t find open either.
Please clarify if I’ve not understood open just to blank
This is HIGHLY intermittent!
Regards,
Pete
Hi Pete,
I have my laptop set to blank the screen only as Ubuntu has been a bit “iffy” on the suspend function thingy for a while now.
Sorry about the confusion, what I meant was: “open” the power settings and set it to blank screen instead of suspend!.
I cannot show you a screenshot now as I am on my normal PC!.
See this bit “The script that finally worked for me:” here:
@wolfman, Thank you for your continued interest and support! [no need for a screen shot, your explanation makes perfect sense]
I read with interest the link you included. My quandary is this intermittent wifi symptom is happening on the same laptop that has been running Ubuntu 14.04 LTS for almost 2 years [never had this symptom] and has just surfaced while testing UM 16. I’m willing to keep investigating, just not willing to label the symptom a bug as yet.
After UM 16 is fully released and if the same symptoms persist I will, of course, use the script.
So does blank the screen only keep the hard drive and cpu fully active?
I think it does Pete although I am not too sure, I believe it does what it says on the box, “Blanks the screen”?.
I think this video is quite helpful https://www.youtube.com/watch?v=n49kukPf8HI