The working workaround for me was to add "radeon.modeset=0 amdgpu.runpm=0 acpi_backlight=intel_backlight" to GRUB_CMDLINE_LINUX_DEFAULT and NOT to switch off switcheroo
In case I disable switcheroo, I have a bug on shutdown. The screen goes to console printing some errors (logs attached) and freezes (caps lock not blinking). ** Attachment added: "kernel.log" https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1656649/+attachment/4804702/+files/kernel.log -- 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/1656649 Title: AMDGPU causes kernel panic with Status in linux package in Ubuntu: Confirmed Bug description: Laptop is Toshiba Satellite S50-B-12R http://www.toshiba.be/fr/discontinued-products/satellite-s50-b-12r/ Graphic card is AMD Radeon R7 M260 Running Ubuntu 16.04, system was unstable when first installed it (a lot of random kernel panic). Problem seemed related to new AMDGPU drivers introduced into new kernels so I tried to disable graphic card by adding radeon.modeset=0 to GRUB_CMDLINE_LINUX_DEFAULT as suggested here http://askubuntu.com/questions/771562/16-04-power-off-discrete- graphics-ati-amd and there http://askubuntu.com/questions/771838/should-i-disable-amd-graphic After this, system is stable except when sleeping. After wake up, I get a kernel panic within 5min (time is random). System logs show a trouble about AMDGPU *ERROR*. I had read that AMD GC was causing trouble with ubuntu 16.04 and I don't care to get it working. For my usage, Intel integrated graphics are enough. But an easy way to disable those drivers in case of trouble should be written on https://wiki.ubuntu.com/XenialXerus/ReleaseNotes#fglrx Looking on forums, a lot of users are affected by this issue. ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: linux-image-4.4.0-59-generic 4.4.0-59.80 ProcVersionSignature: Ubuntu 4.4.0-59.80-generic 4.4.35 Uname: Linux 4.4.0-59-generic x86_64 ApportVersion: 2.20.1-0ubuntu2.4 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: axtux 1963 F.... pulseaudio /dev/snd/controlC1: axtux 1963 F.... pulseaudio CurrentDesktop: Unity Date: Sun Jan 15 13:29:26 2017 HibernationDevice: RESUME=UUID=d3a0be1f-38a0-475c-863c-38ca63b47d81 InstallationDate: Installed on 2016-11-01 (74 days ago) InstallationMedia: Ubuntu 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719) MachineType: TOSHIBA SATELLITE S50-B ProcFB: 0 inteldrmfb ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.4.0-59-generic.efi.signed root=/dev/mapper/ubuntu--vg-root ro quiet splash radeon.modeset=0 vt.handoff=7 RelatedPackageVersions: linux-restricted-modules-4.4.0-59-generic N/A linux-backports-modules-4.4.0-59-generic N/A linux-firmware 1.157.6 SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 08/26/2014 dmi.bios.vendor: INSYDE Corp. dmi.bios.version: 1.80 dmi.board.asset.tag: Type2 - Board Asset Tag dmi.board.name: Type2 - Board Product Name1 dmi.board.vendor: Type2 - Board Vendor Name1 dmi.board.version: Type2 - Board Version dmi.chassis.asset.tag: No Asset Tag dmi.chassis.type: 10 dmi.chassis.vendor: OEM Chassis ManuFacturer dmi.chassis.version: OEM Chassis Version dmi.modalias: dmi:bvnINSYDECorp.:bvr1.80:bd08/26/2014:svnTOSHIBA:pnSATELLITES50-B:pvrPSPQ6E-01K002BT:rvnType2-BoardVendorName1:rnType2-BoardProductName1:rvrType2-BoardVersion:cvnOEMChassisManuFacturer:ct10:cvrOEMChassisVersion: dmi.product.name: SATELLITE S50-B dmi.product.version: PSPQ6E-01K002BT dmi.sys.vendor: TOSHIBA To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1656649/+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
