Oops, it was either acpi_osi=! or acpi_osi='Windows 2009' that was causing the problem. I had copied them in to try and get the nvidia card working after resume, but it turns out they aren't needed for the nvidia card to work anyway.
Sorry for the noise. ** Changed in: upower (Ubuntu) Status: Incomplete => Invalid ** Changed in: linux (Ubuntu) Status: Incomplete => Invalid -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to upower in Ubuntu. https://bugs.launchpad.net/bugs/1812161 Title: Screen backlight control does not work in Disco on Dell XPS 9560 Status in linux package in Ubuntu: Invalid Status in upower package in Ubuntu: Invalid Bug description: When I press the screen backlight up/down buttons, gnome-shell pops up the backlight control window saying that the backlight is being adjusted, but the actual screen brightness does not change. The problem is that gnome is adjusting /sys/class/backlight/acpi_video0/brightness instead of /sys/class/backlight/intel_backlight/brightness. If I manually change the latter as root with, say: root@xps-9560:~ echo 600 > /sys/class/backlight/intel_backlight/brightness then the brightness changes. The brightness control worked fine in Cosmic on this laptop, so this is a regression. ProblemType: Bug DistroRelease: Ubuntu 19.04 Package: xorg 1:7.7+19ubuntu8 ProcVersionSignature: Ubuntu 4.18.0-13.14-generic 4.18.17 Uname: Linux 4.18.0-13-generic x86_64 .tmp.unity_support_test.0: ApportVersion: 2.20.10-0ubuntu18 Architecture: amd64 CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins' CompositorRunning: None CurrentDesktop: ubuntu:GNOME Date: Thu Jan 17 14:47:37 2019 DistUpgraded: 2019-01-15 23:10:12,938 DEBUG Running PostInstallScript: './xorg_fix_proprietary.py' DistroCodename: disco DistroVariant: ubuntu DkmsStatus: bbswitch, 0.8, 4.18.0-13-generic, x86_64: installed bbswitch, 0.8, 4.20.0-042000-generic, x86_64: installed bbswitch, 0.8, 4.20.3-042003-generic, x86_64: installed nvidia, 415.27, 4.20.0-042000-generic, x86_64: installed nvidia, 415.27, 4.20.3-042003-generic, x86_64: installed ExtraDebuggingInterest: Yes GraphicsCard: Intel Corporation Device [8086:591b] (rev 04) (prog-if 00 [VGA controller]) Subsystem: Dell Device [1028:07be] Subsystem: Dell GP107M [GeForce GTX 1050 Mobile] [1028:07be] InstallationDate: Installed on 2017-08-16 (518 days ago) InstallationMedia: Ubuntu 17.04 "Zesty Zapus" - Release amd64 (20170412) MachineType: Dell Inc. XPS 15 9560 ProcKernelCmdLine: BOOT_IMAGE=/@/boot/vmlinuz-4.18.0-13-generic root=UUID=0eb64261-6dff-464a-8373-596794c1fafe ro rootflags=subvol=@ quiet splash acpi_rev_override=5 scsi_mod.use_blk_mq=1 i915.modeset=1 nouveau.runpm=0 rcutree.rcu_idle_gp_delay=1 acpi_osi=! "acpi_osi=Windows 2009" SourcePackage: xorg Symptom: display UpgradeStatus: Upgraded to disco on 2019-01-15 (1 days ago) dmi.bios.date: 10/02/2018 dmi.bios.vendor: Dell Inc. dmi.bios.version: 1.12.1 dmi.board.name: 05FFDN dmi.board.vendor: Dell Inc. dmi.board.version: A00 dmi.chassis.type: 10 dmi.chassis.vendor: Dell Inc. dmi.modalias: dmi:bvnDellInc.:bvr1.12.1:bd10/02/2018:svnDellInc.:pnXPS159560:pvr:rvnDellInc.:rn05FFDN:rvrA00:cvnDellInc.:ct10:cvr: dmi.product.family: XPS dmi.product.name: XPS 15 9560 dmi.product.sku: 07BE dmi.sys.vendor: Dell Inc. version.compiz: compiz 1:0.9.13.1+19.04.20190103-0ubuntu1 version.libdrm2: libdrm2 2.4.95-1 version.libgl1-mesa-dri: libgl1-mesa-dri 18.2.8-2ubuntu1 version.libgl1-mesa-glx: libgl1-mesa-glx 18.2.8-2ubuntu1 version.xserver-xorg-core: xserver-xorg-core 2:1.20.3-1ubuntu1 version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:18.1.0-1 version.xserver-xorg-video-intel: xserver-xorg-video-intel N/A version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.15-3 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1812161/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp