Under 4.18-rc3 from http://kernel.ubuntu.com/~kernel- ppa/mainline/v4.18-rc3/ the symptoms appear identical to those under 4.15.0-25-generic.
I tested mainline 4.17, 4.17.2, 4.17.3, 4.17.4 and 4.18-rc2 from the kernel.ubuntu.com, which all displayed the original symptoms reported for this bug. Correction/clarification: Previously, I failed to test whether the temporal dithering appeared in virtual consoles under 4.13.0-41. I only tested to see whether it affected virtual consoles on kernels where it also affected X. It turns out that the dithering has always been present in virtual consoles at least as far back as 4.13.0-31, but it did not appear under X until 4.13.0-43. I will amend the bug description to reflect this. The issue with semi-transparent backgrounds in Plasma widgets may be unrelated, as this is now appearing under all kernels I've tried booting. ** Description changed: I am experiencing a regression in linux-image-generic-hwe-16.04 with Intel HD Graphics 530 (Core i5-6600T), starting in 4.13.0-43 (considering only kernels which appear in my GRUB menu). Some form of spatio-temporal dithering has been enabled. This is causing a shimmering effect and visible dithering patterns (like woven textile) which are noticeable on photographs and areas of similar colour. 1px borders in the UI can appear to have a "marching ants" effect. - The effect is visible both under Xorg and in a virtual console - (Ctrl+Alt+F1), if the displayed colours are suitable to trigger it. + The effect is visible under Xorg if the displayed colours are suitable + to trigger it. - Booting 4.13.0-41 eliminates the temporal dithering. + The effect is also visible a virtual console (Ctrl+Alt+F1) if suitable + colours are displayed, but it seems that the presence of the effect in + virtual consoles predates its appearance under Xorg and the reporting of + this bug, going back at least as far as 4.13.0-31, but with no reason to + believe it does not go back further (besides lack of testing). + + Reverting from 4.13.0-43 by booting 4.13.0-41 eliminates the temporal + dithering in Xorg. This occurs on a (presumed) 6bpp laptop LCD panel, so dithering is necessary, but in previous kernels only a form of spatial dithering is applied, which is less visually obvious. Concurrent with the temporal dithering, I have also noticed general poor graphical performance with the affected kernels. E.g. 50fps and 60fps video playback is choppy, sometimes slow redraw and other graphical glitches on UI elements. Like the temporal dithering, these additional problems disappear if I revert to 4.13.0-41. --- ApportVersion: 2.20.1-0ubuntu2.18 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: patrick 1976 F.... pulseaudio DistroRelease: Ubuntu 16.04 EcryptfsInUse: Yes HibernationDevice: RESUME=UUID=72e179a8-b27c-42d3-9523-8f1cceacaa64 InstallationDate: Installed on 2016-09-16 (634 days ago) InstallationMedia: Kubuntu 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719) MachineType: PC Specialist Limited N350DW Package: linux (not installed) ProcFB: 0 inteldrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.13.0-45-generic root=UUID=deeef076-c1e1-47ec-8ee4-d3b56fa179f9 ro quiet splash vt.handoff=7 ProcVersionSignature: Ubuntu 4.13.0-45.50~16.04.1-generic 4.13.16 RelatedPackageVersions: linux-restricted-modules-4.13.0-45-generic N/A linux-backports-modules-4.13.0-45-generic N/A linux-firmware 1.157.19 Tags: xenial xenial Uname: Linux 4.13.0-45-generic x86_64 UnreportableReason: The report belongs to a package that is not installed. UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm cdrom dip lp lpadmin plugdev sambashare sudo vboxusers _MarkForUpload: False dmi.bios.date: 05/26/2016 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: 5.11 dmi.board.asset.tag: Tag 12345 dmi.board.name: N350DW dmi.board.vendor: CLEVO dmi.board.version: Not Applicable dmi.chassis.asset.tag: No Asset Tag dmi.chassis.type: 10 dmi.chassis.vendor: No Enclosure dmi.chassis.version: N/A dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr5.11:bd05/26/2016:svnPCSpecialistLimited:pnN350DW:pvrNotApplicable:rvnCLEVO:rnN350DW:rvrNotApplicable:cvnNoEnclosure:ct10:cvrN/A: dmi.product.family: Not Applicable dmi.product.name: N350DW dmi.product.version: Not Applicable dmi.sys.vendor: PC Specialist Limited ** Description changed: I am experiencing a regression in linux-image-generic-hwe-16.04 with Intel HD Graphics 530 (Core i5-6600T), starting in 4.13.0-43 (considering only kernels which appear in my GRUB menu). Some form of spatio-temporal dithering has been enabled. This is causing a shimmering effect and visible dithering patterns (like woven textile) which are noticeable on photographs and areas of similar colour. 1px borders in the UI can appear to have a "marching ants" effect. The effect is visible under Xorg if the displayed colours are suitable to trigger it. - The effect is also visible a virtual console (Ctrl+Alt+F1) if suitable - colours are displayed, but it seems that the presence of the effect in - virtual consoles predates its appearance under Xorg and the reporting of - this bug, going back at least as far as 4.13.0-31, but with no reason to - believe it does not go back further (besides lack of testing). + The effect is also visible in a virtual console (Ctrl+Alt+F1) if + suitable colours are displayed, but it seems that the presence of the + effect in virtual consoles predates its appearance under Xorg and the + reporting of this bug, going back at least as far as 4.13.0-31, but with + no reason to believe it does not go back further (besides lack of + testing). Reverting from 4.13.0-43 by booting 4.13.0-41 eliminates the temporal dithering in Xorg. This occurs on a (presumed) 6bpp laptop LCD panel, so dithering is necessary, but in previous kernels only a form of spatial dithering is applied, which is less visually obvious. Concurrent with the temporal dithering, I have also noticed general poor graphical performance with the affected kernels. E.g. 50fps and 60fps video playback is choppy, sometimes slow redraw and other graphical glitches on UI elements. Like the temporal dithering, these additional problems disappear if I revert to 4.13.0-41. --- ApportVersion: 2.20.1-0ubuntu2.18 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: patrick 1976 F.... pulseaudio DistroRelease: Ubuntu 16.04 EcryptfsInUse: Yes HibernationDevice: RESUME=UUID=72e179a8-b27c-42d3-9523-8f1cceacaa64 InstallationDate: Installed on 2016-09-16 (634 days ago) InstallationMedia: Kubuntu 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719) MachineType: PC Specialist Limited N350DW Package: linux (not installed) ProcFB: 0 inteldrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.13.0-45-generic root=UUID=deeef076-c1e1-47ec-8ee4-d3b56fa179f9 ro quiet splash vt.handoff=7 ProcVersionSignature: Ubuntu 4.13.0-45.50~16.04.1-generic 4.13.16 RelatedPackageVersions: linux-restricted-modules-4.13.0-45-generic N/A linux-backports-modules-4.13.0-45-generic N/A linux-firmware 1.157.19 Tags: xenial xenial Uname: Linux 4.13.0-45-generic x86_64 UnreportableReason: The report belongs to a package that is not installed. UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm cdrom dip lp lpadmin plugdev sambashare sudo vboxusers _MarkForUpload: False dmi.bios.date: 05/26/2016 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: 5.11 dmi.board.asset.tag: Tag 12345 dmi.board.name: N350DW dmi.board.vendor: CLEVO dmi.board.version: Not Applicable dmi.chassis.asset.tag: No Asset Tag dmi.chassis.type: 10 dmi.chassis.vendor: No Enclosure dmi.chassis.version: N/A dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr5.11:bd05/26/2016:svnPCSpecialistLimited:pnN350DW:pvrNotApplicable:rvnCLEVO:rnN350DW:rvrNotApplicable:cvnNoEnclosure:ct10:cvrN/A: dmi.product.family: Not Applicable dmi.product.name: N350DW dmi.product.version: Not Applicable dmi.sys.vendor: PC Specialist Limited -- 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/1776642 Title: Temporal dithering and impaired graphical performance started appearing on Intel HD 530 graphics Status in linux package in Ubuntu: Confirmed Bug description: I am experiencing a regression in linux-image-generic-hwe-16.04 with Intel HD Graphics 530 (Core i5-6600T), starting in 4.13.0-43 (considering only kernels which appear in my GRUB menu). Some form of spatio-temporal dithering has been enabled. This is causing a shimmering effect and visible dithering patterns (like woven textile) which are noticeable on photographs and areas of similar colour. 1px borders in the UI can appear to have a "marching ants" effect. The effect is visible under Xorg if the displayed colours are suitable to trigger it. The effect is also visible in a virtual console (Ctrl+Alt+F1) if suitable colours are displayed, but it seems that the presence of the effect in virtual consoles predates its appearance under Xorg and the reporting of this bug, going back at least as far as 4.13.0-31, but with no reason to believe it does not go back further (besides lack of testing). Reverting from 4.13.0-43 by booting 4.13.0-41 eliminates the temporal dithering in Xorg. This occurs on a (presumed) 6bpp laptop LCD panel, so dithering is necessary, but in previous kernels only a form of spatial dithering is applied, which is less visually obvious. Concurrent with the temporal dithering, I have also noticed general poor graphical performance with the affected kernels. E.g. 50fps and 60fps video playback is choppy, sometimes slow redraw and other graphical glitches on UI elements. Like the temporal dithering, these additional problems disappear if I revert to 4.13.0-41. --- ApportVersion: 2.20.1-0ubuntu2.18 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: patrick 1976 F.... pulseaudio DistroRelease: Ubuntu 16.04 EcryptfsInUse: Yes HibernationDevice: RESUME=UUID=72e179a8-b27c-42d3-9523-8f1cceacaa64 InstallationDate: Installed on 2016-09-16 (634 days ago) InstallationMedia: Kubuntu 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719) MachineType: PC Specialist Limited N350DW Package: linux (not installed) ProcFB: 0 inteldrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.13.0-45-generic root=UUID=deeef076-c1e1-47ec-8ee4-d3b56fa179f9 ro quiet splash vt.handoff=7 ProcVersionSignature: Ubuntu 4.13.0-45.50~16.04.1-generic 4.13.16 RelatedPackageVersions: linux-restricted-modules-4.13.0-45-generic N/A linux-backports-modules-4.13.0-45-generic N/A linux-firmware 1.157.19 Tags: xenial xenial Uname: Linux 4.13.0-45-generic x86_64 UnreportableReason: The report belongs to a package that is not installed. UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm cdrom dip lp lpadmin plugdev sambashare sudo vboxusers _MarkForUpload: False dmi.bios.date: 05/26/2016 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: 5.11 dmi.board.asset.tag: Tag 12345 dmi.board.name: N350DW dmi.board.vendor: CLEVO dmi.board.version: Not Applicable dmi.chassis.asset.tag: No Asset Tag dmi.chassis.type: 10 dmi.chassis.vendor: No Enclosure dmi.chassis.version: N/A dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr5.11:bd05/26/2016:svnPCSpecialistLimited:pnN350DW:pvrNotApplicable:rvnCLEVO:rnN350DW:rvrNotApplicable:cvnNoEnclosure:ct10:cvrN/A: dmi.product.family: Not Applicable dmi.product.name: N350DW dmi.product.version: Not Applicable dmi.sys.vendor: PC Specialist Limited To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1776642/+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
