Comment 0 for bug 1746357

Boot looping since initial 14.04 install (nomodeset was the workaround I used).
I recently upgraded to 16.04.3 and fell in the same issue as upgrade overwrote my /etc/default/grub without prompting, AFAIR.
Digging the issue I found another possible workaround on the web... that works too, but using the AMD non-free driver : radeon.dpm=0

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: linux-image-4.4.0-112-generic 4.4.0-112.135
ProcVersionSignature: Ubuntu 4.4.0-112.135-generic 4.4.98
Uname: Linux 4.4.0-112-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.15
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: fab 1962 F.... pulseaudio
 /dev/snd/controlC0: fab 1962 F.... pulseaudio
CurrentDesktop: Unity
Date: Tue Jan 30 22:46:13 2018
HibernationDevice: RESUME=UUID=66392631-7c4f-4773-8614-4c5ea0913890
InstallationDate: Installed on 2014-07-26 (1284 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417)
IwConfig:
 lo no wireless extensions.

 eth1 no wireless extensions.
MachineType: MSI MS-7721
ProcFB: 0 radeondrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.4.0-112-generic root=UUID=09ecdff0-44fe-437e-8063-deabc6feb00e ro radeon.dpm=0
RelatedPackageVersions:
 linux-restricted-modules-4.4.0-112-generic N/A
 linux-backports-modules-4.4.0-112-generic N/A
 linux-firmware 1.157.15
RfKill:

SourcePackage: linux
UpgradeStatus: Upgraded to xenial on 2018-01-16 (14 days ago)
dmi.bios.date: 12/15/2014
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: V30.6
dmi.board.asset.tag: To be filled by O.E.M.
dmi.board.name: A88XM-E35 (MS-7721)
dmi.board.vendor: MSI
dmi.board.version: 6.0
dmi.chassis.asset.tag: To Be Filled By O.E.M.
dmi.chassis.type: 3
dmi.chassis.vendor: MSI
dmi.chassis.version: 6.0
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrV30.6:bd12/15/2014:svnMSI:pnMS-7721:pvr6.0:rvnMSI:rnA88XM-E35(MS-7721):rvr6.0:cvnMSI:ct3:cvr6.0:
dmi.product.name: MS-7721
dmi.product.version: 6.0
dmi.sys.vendor: MSI