Hi again, Still same problem, wakeup from hibernation freezes at some time, with latest kernel (4.4.0-31), that is to say the system becomes totally unresponsive, the screen may go black or not.
It seems that the system is not always able to write something in logs when this occurs : in /var/log/kern.log there is sometimes nothing, sometimes a general protection fault, sometimes one line with only @@@@@@@@@@@@@ symbols (??). In the meantime, suspend to ram is absolutely stable. Nevertheless, I noticed that if I switch ON the nvidia card (*) just before hibernating, freezes seem to occur less often. Again, if anyone has some hints about how to debug. Regards (*) The T440s has got two graphic cards, integrated intel and nvidia G730M, the nvidia card is switched OFF by default at boot with bbswitch module, I can switch it ON with "echo ON > /proc/acpi/bbswitch" -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1566302 Title: Ubuntu 16.04: Suspend freezes the system after upgrade to linux image 4.4.0-16 Status in linux package in Ubuntu: Won't Fix Bug description: I'm using ubuntu 16.04 on a XPS 15 9550. Suspend/resume worked flawlessly with linux image 4.4.0-15, and after standard upgrade yesterday (5/04/2016) which installed image 4.4.0-16, the system freezes when attempting a suspend. I get no response from the system (nor keyboard, nor screen, nor touchpad), but it gets very hot, so that it must be running something. Booting with 4.4.0-15 makes the suspend to work perfectly. ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: linux-image-extra-4.4.0-16-generic 4.4.0-16.32 ProcVersionSignature: Ubuntu 4.4.0-15.31-generic 4.4.6 Uname: Linux 4.4.0-15-generic x86_64 ApportVersion: 2.20.1-0ubuntu1 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: macias 1770 F.... pulseaudio CurrentDesktop: X-Cinnamon Date: Tue Apr 5 14:56:17 2016 HibernationDevice: RESUME=UUID=4180adfa-3852-4a96-86b4-f3696448c743 InstallationDate: Installed on 2016-03-07 (28 days ago) InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Alpha amd64 (20160304) Lsusb: Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 001 Device 003: ID 04f3:21d5 Elan Microelectronics Corp. Bus 001 Device 002: ID 0a5c:6410 Broadcom Corp. Bus 001 Device 004: ID 1bcf:2b95 Sunplus Innovation Technology Inc. Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub MachineType: Dell Inc. XPS 15 9550 ProcEnviron: LANGUAGE=es_ES PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=es_ES.UTF-8 SHELL=/bin/bash ProcFB: 0 inteldrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.4.0-15-generic.efi.signed root=UUID=673f4658-75f8-4c01-bcd8-0af860269699 ro quiet splash vt.handoff=7 RelatedPackageVersions: linux-restricted-modules-4.4.0-15-generic N/A linux-backports-modules-4.4.0-15-generic N/A linux-firmware 1.157 SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 01/25/2016 dmi.bios.vendor: Dell Inc. dmi.bios.version: 01.01.19 dmi.board.name: 0N7TVV dmi.board.vendor: Dell Inc. dmi.board.version: A00 dmi.chassis.type: 9 dmi.chassis.vendor: Dell Inc. dmi.modalias: dmi:bvnDellInc.:bvr01.01.19:bd01/25/2016:svnDellInc.:pnXPS159550:pvr:rvnDellInc.:rn0N7TVV:rvrA00:cvnDellInc.:ct9:cvr: dmi.product.name: XPS 15 9550 dmi.sys.vendor: Dell Inc. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1566302/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp