No need to run any bisecting. You can see where the change was with cgit ( https://git.kernel.org/cgit/linux/kernel/git/stable/linux- stable.git/commit/?id=919cf555c04e16dafb1fba56904eb23889a812c3 ). Technically, it's not fixed upstream. They just applied the aforementioned workaround of disabling DPM for Northern Islands until they figure out how to fix it. Another bug report on bugzilla related to the bug can be found here: https://bugzilla.kernel.org/show_bug.cgi?id=68571 which shows how even with kernel 3.14, manually enabling DPM, since it is disabled by default now, with radeon.dpm=1 still causes the problems. In kernel 3.12 and prior, DPM was disabled by default since it was buggy, but for some reason it was enabled by default with 3.13, leading to these problems.
** Bug watch added: Linux Kernel Bug Tracker #68571 http://bugzilla.kernel.org/show_bug.cgi?id=68571 -- 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/1297464 Title: 1002:6739 14.04 randomly reboots Status in “linux” package in Ubuntu: Confirmed Bug description: I've noticed after installing Ubuntu 14.04 on my computer, that a DPM issue exists. DPM needs to be disabled by default like in kernel 3.14 so that the live CD or desktop session does not instantly reboot the machine. WORKAROUND: Edit grub.cfg on the bootable flash drive and adding radeon.dpm=0 to the boot options, along with cd'ing to /target/etc/default and editing grub with the same change before rebooting after installation to bypass it. --- ApportVersion: 2.14.1-0ubuntu3 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: ubuntu 2789 F.... pulseaudio /dev/snd/controlC1: ubuntu 2789 F.... pulseaudio CasperVersion: 1.340 CurrentDesktop: Unity DistroRelease: Ubuntu 14.04 IwConfig: eth0 no wireless extensions. lo no wireless extensions. LiveMediaBuild: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417) MachineType: System manufacturer System Product Name Package: linux (not installed) ProcEnviron: TERM=xterm PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_US.UTF-8 SHELL=/bin/bash ProcFB: 0 radeondrmfb ProcKernelCmdLine: BOOT_IMAGE=(loop)/casper/vmlinuz.efi root=UUID=E3B4-EDF6 debian-installer/language=en keyboard-configuration/layoutcode=us iso-scan/filename=/username-14.04-desktop-amd64.iso boot=casper file=/cdrom/preseed/username.seed noprompt quiet splash radeon.dpm=0 -- ProcVersionSignature: Ubuntu 3.13.0-24.46-generic 3.13.9 RelatedPackageVersions: linux-restricted-modules-3.13.0-24-generic N/A linux-backports-modules-3.13.0-24-generic N/A linux-firmware 1.127 RfKill: Tags: trusty Uname: Linux 3.13.0-24-generic x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo _MarkForUpload: True dmi.bios.date: 06/17/2010 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: 2102 dmi.board.asset.tag: To Be Filled By O.E.M. dmi.board.name: M4A79XTD EVO dmi.board.vendor: ASUSTeK Computer INC. dmi.board.version: Rev X.0X dmi.chassis.asset.tag: Asset-1234567890 dmi.chassis.type: 3 dmi.chassis.vendor: Chassis Manufacture dmi.chassis.version: Chassis Version dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr2102:bd06/17/2010:svnSystemmanufacturer:pnSystemProductName:pvrSystemVersion:rvnASUSTeKComputerINC.:rnM4A79XTDEVO:rvrRevX.0X:cvnChassisManufacture:ct3:cvrChassisVersion: dmi.product.name: System Product Name dmi.product.version: System Version dmi.sys.vendor: System manufacturer To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1297464/+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
