On my desktop when I set "System settings > Power > Suspend when inactive for" to any time (5 minutes, say), and wait, Ubuntu suspends. When I power my desktop back on, it boots without the usual chatter on the screen and the screen stays entirely blank (the monitor is in power-save mode). At that point the only workaround is to force a reboot by holding down the power button for 4 seconds, and go through the ordinary boot process.
This appears to be the same symptoms as Bug#1283938, the last comment of which says "file a bug by running 'ubuntu-bug linux'", which is what I've done here. I have had the problem for years but have not reported it until today.
My desktop has an Asus M4N78 Pro motherboard, which uses an NVIDIA GeForce 8300 chipset. lspci reports the graphics controller as "NVIDIA Corporation C77 [GeForce 8300] (rev a2)". "Software & Updates" says I am using "NVIDIA legacy binary driver - version 304.135 from nvidia-304 (proprietary)". As discussed in Bug#1639180 comment#65, I cannot use the latest NVIDIA driver as it has so many artifacts on the screen that it is unusable.
ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: linux-image-4.4.0-72-generic 4.4.0-72.93
ProcVersionSignature: Ubuntu 4.4.0-72.93-generic 4.4.49
Uname: Linux 4.4.0-72-generic i686
NonfreeKernelModules: nvidia
ApportVersion: 2.20.1-0ubuntu2.5
Architecture: i386
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/controlC0: eggert 1825 F.... pulseaudio
/dev/snd/controlC1: eggert 1825 F.... pulseaudio
CurrentDesktop: Unity
Date: Sun Apr 16 09:38:00 2017
HibernationDevice: RESUME=UUID=433ca071-21cd-44b7-9b81-2b73c0463790
InstallationDate: Installed on 2014-04-27 (1084 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release i386 (20140417)
MachineType: System manufacturer System Product Name
ProcFB:
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.4.0-72-generic root=UUID=0d7c67e2-db5b-493a-890b-90121ad2ee20 ro quiet splash acpi_enforce_resources=lax
RelatedPackageVersions:
linux-restricted-modules-4.4.0-72-generic N/A
linux-backports-modules-4.4.0-72-generic N/A
linux-firmware 1.157.8
RfKill:
0: phy0: Wireless LAN
Soft blocked: no
Hard blocked: no
SourcePackage: linux
UpgradeStatus: Upgraded to xenial on 2016-04-22 (358 days ago)
dmi.bios.date: 07/10/2009
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 1004
dmi.board.asset.tag: To Be Filled By O.E.M.
dmi.board.name: M4N78 PRO
dmi.board.vendor: ASUSTeK Computer INC.
dmi.board.version: Rev 1.xx
dmi.chassis.asset.tag: Asset-1234567890
dmi.chassis.type: 3
dmi.chassis.vendor: Chassis Manufacture
dmi.chassis.version: Chassis Version
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr1004:bd07/10/2009:svnSystemmanufacturer:pnSystemProductName:pvrSystemVersion:rvnASUSTeKComputerINC.:rnM4N78PRO:rvrRev1.xx:cvnChassisManufacture:ct3:cvrChassisVersion:
dmi.product.name: System Product Name
dmi.product.version: System Version
dmi.sys.vendor: System manufacturer
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