Donk, the next step is to fully reverse commit bisect from kernel 4.15 to 4.16.18, in order to identify the latest kernel commit that did not work followed immediately by the next kernel commit that did work. This will allow a consideration of the fix commit for backporting. Could you please do this following https://wiki.ubuntu.com/Kernel/KernelBisection ? This article was written for folks who don't know anything about linux, so it's easy to follow.
Please note, finding adjacent kernel versions, or providing a commit without testing it and reverting it is not fully reverse commit bisecting. Also, the kernel release names are irrelevant for the purposes of bisecting. It is most helpful that after the fix commit (not kernel version) has been confirmed via testing, you then mark this report Status Confirmed. Thank you for your help. ** Changed in: linux (Ubuntu) Status: Confirmed => Incomplete -- 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/1785481 Title: amdgpu WQHD resolution(2560 × 1440) not available Status in linux package in Ubuntu: Incomplete Bug description: Hello, I use ubuntu 16.04 with hwe stack and an Radeon R9 285. With kernel 4.13 and older, I can use a resolution of 2560x1440. But, since the upgrade to kernel 4.15, I'm limited to the 1920x1200. I have attached the output of xrandr on both kernel. My screen (Dell U2713HM) is plugged to the output DVI-1. With a kernel 4.13, the output is detected as a DVI-I. But with a kernel 4.15, the output is detected as a DVI-D. ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: linux-image-4.15.0-29-generic 4.15.0-29.31~16.04.1 ProcVersionSignature: Ubuntu 4.15.0-29.31~16.04.1-generic 4.15.18 Uname: Linux 4.15.0-29-generic x86_64 ApportVersion: 2.20.1-0ubuntu2.18 Architecture: amd64 CurrentDesktop: Unity Date: Sun Aug 5 16:46:32 2018 SourcePackage: linux-signed-hwe UpgradeStatus: Upgraded to xenial on 2016-12-17 (595 days ago) --- ApportVersion: 2.20.1-0ubuntu2.18 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: frederic 2366 F.... pulseaudio /dev/snd/controlC1: frederic 2366 F.... pulseaudio CurrentDesktop: Unity DistroRelease: Ubuntu 16.04 HibernationDevice: RESUME=/dev/mapper/Fred_SSD-Fred_Swap IwConfig: lo no wireless extensions. em1 no wireless extensions. MachineType: ASUS All Series Package: linux (not installed) ProcFB: 0 amdgpudrmfb ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.15.0-29-generic root=/dev/mapper/Fred_SSD-Fred_Root ro quiet ProcVersionSignature: Ubuntu 4.15.0-29.31~16.04.1-generic 4.15.18 RelatedPackageVersions: linux-restricted-modules-4.15.0-29-generic N/A linux-backports-modules-4.15.0-29-generic N/A linux-firmware 1.157.20 RfKill: Tags: xenial Uname: Linux 4.15.0-29-generic x86_64 UpgradeStatus: Upgraded to xenial on 2016-12-17 (596 days ago) UserGroups: adm cdrom dip lp lpadmin plugdev sambashare scanner sudo video _MarkForUpload: True dmi.bios.date: 10/28/2015 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: 3003 dmi.board.asset.tag: To be filled by O.E.M. dmi.board.name: MAXIMUS VII RANGER dmi.board.vendor: ASUSTeK COMPUTER INC. dmi.board.version: Rev 1.xx dmi.chassis.asset.tag: To Be Filled By O.E.M. dmi.chassis.type: 3 dmi.chassis.vendor: To Be Filled By O.E.M. dmi.chassis.version: To Be Filled By O.E.M. dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr3003:bd10/28/2015:svnASUS:pnAllSeries:pvrSystemVersion:rvnASUSTeKCOMPUTERINC.:rnMAXIMUSVIIRANGER:rvrRev1.xx:cvnToBeFilledByO.E.M.:ct3:cvrToBeFilledByO.E.M.: dmi.product.family: ASUS MB dmi.product.name: All Series dmi.product.version: System Version dmi.sys.vendor: ASUS To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1785481/+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