Confirming problem exactly as described in original description. Freezes are frequently triggered by video playback in browsers, but also in normal browser use. Chrome and other browsers using the Blink rendering engine (like Opera) trigger freezes much more often than firefox. But regularly I can trigger a freeze even in Firefox by showing a video on youtube in fullscreen mode for in than 15 minutes. We provide Ubuntu for 700+ users at a school and cannot switch from 14.04 to 16.04 while this problem persists. It was already present in the last updates to 14.04 we made around march 2016, if this helps. Appreciating your effort on solving this bug!
** Attachment added: "Hardware configuration as of lshw" https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1575467/+attachment/4675111/+files/lshw.txt -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to the bug report. https://bugs.launchpad.net/bugs/1575467 Title: [Dell Inspiron 3451] WARNING: CPU: 1 PID: 1297 at /build/linux-lts- utopic-vy2yyy/linux-lts- utopic-3.16.0/drivers/gpu/drm/i915/intel_display.c:1743 vlv_wait_port_ready+0x126/0x170 [i915]() Status in linux package in Ubuntu: In Progress Bug description: After upgrading from stock Ubuntu 14.04 to 16.04 my laptop consistently freezes up and is unresponsive to keyboard or mouse. The only way is to do a hard shutdown. I'm usually in a browser when this happens, and often watching a video or two. It seems to happen more often in Google Chrome than Firefox, but it happens with both. It has happened at least once with no videos loaded. I haven’t observed it freeze / hang when I’m not in a browser, but that's mainly what i use my laptop for, so that's where most of my time is spent. Call trace: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1575467/+attachment/4648682/+files/kern.log.2.gz --- ApportVersion: 2.20.1-0ubuntu2 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: andrew 1949 F.... pulseaudio DistroRelease: Ubuntu 16.04 HibernationDevice: RESUME=UUID=e8aaee7c-d956-4519-94f0-cf7aad745020 InstallationDate: Installed on 2015-08-08 (263 days ago) InstallationMedia: Ubuntu 14.04.2 LTS "Trusty Tahr" - Release amd64 (20150218.1) MachineType: Dell Inc. Inspiron 3451 Package: linux (not installed) ProcEnviron: LANGUAGE=en_US TERM=xterm-256color PATH=(custom, no user) LANG=en_US.UTF-8 SHELL=/bin/bash ProcFB: 0 inteldrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.4.0-21-generic.efi.signed root=UUID=d01f07be-c906-4024-8eef-a58ba3935298 ro quiet splash vt.handoff=7 ProcVersionSignature: Ubuntu 4.4.0-21.37-generic 4.4.6 PulseList: Error: command ['pacmd', 'list'] failed with exit code 1: Home directory not accessible: Permission denied No PulseAudio daemon running, or not running as session daemon. RelatedPackageVersions: linux-restricted-modules-4.4.0-21-generic N/A linux-backports-modules-4.4.0-21-generic N/A linux-firmware 1.157 Tags: xenial Uname: Linux 4.4.0-21-generic x86_64 UpgradeStatus: Upgraded to xenial on 2016-04-22 (4 days ago) UserGroups: _MarkForUpload: True dmi.bios.date: 12/05/2014 dmi.bios.vendor: Dell Inc. dmi.bios.version: A00 dmi.board.name: 0H4MK6 dmi.board.vendor: Dell Inc. dmi.board.version: A00 dmi.chassis.type: 8 dmi.chassis.vendor: Dell Inc. dmi.chassis.version: Not Specified dmi.modalias: dmi:bvnDellInc.:bvrA00:bd12/05/2014:svnDellInc.:pnInspiron3451:pvrA00:rvnDellInc.:rn0H4MK6:rvrA00:cvnDellInc.:ct8:cvrNotSpecified: dmi.product.name: Inspiron 3451 dmi.product.version: A00 dmi.sys.vendor: Dell Inc. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1575467/+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