I'm experiencing this too, using Ubuntu 13.10 on Dell E6530 laptop. After pressing Fn+up/down, nothing happens for 1-2s, then the brightness is changed, then the OSD for it pops up. I can only change the backlight in steps with this frequency.
During that waiting, the whole system (terminals, mouse, keyboard, ...) becomes sluggish, CPU meter does *not* go up. I don't remember to change anything related since the install. The backlight stepping works find on the older Dell V13 laptop using Ubuntu 13.04 (though it had its own problems in the past -- one direction keypress behind). -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to gnome-power-manager in Ubuntu. https://bugs.launchpad.net/bugs/847001 Title: Adjusting display brightness is very slow on several Dell laptops Status in “gnome-power-manager” package in Ubuntu: Confirmed Bug description: Changing the brightness via FN key combination or via the brightness applet is very slow. the CPUs don't seem to go to 100%, but the adjustment process seems relatively slow. The mouse cursor is also sluggish. Reinstalled the OS twice, but not because of this issue and the problem seems to persist. ProblemType: Bug DistroRelease: Ubuntu 11.04 Package: gnome-power-manager 2.32.0-2ubuntu2.1 ProcVersionSignature: Ubuntu 2.6.38-11.48-generic 2.6.38.8 Uname: Linux 2.6.38-11-generic x86_64 Architecture: amd64 Date: Sun Sep 11 15:29:02 2011 GnomeSessionIdleInhibited: No GnomeSessionInhibitors: None GnomeSessionSuspendInhibited: No InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release amd64 (20110427) MachineType: Dell Inc. Latitude E5410 ProcEnviron: LANGUAGE=en_US:en LANG=en_US.UTF-8 SHELL=/bin/bash ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.38-11-generic root=UUID=0dfaacc9-c19d-425b-963d-dabb87ae18bc ro quiet splash vt.handoff=7 SourcePackage: gnome-power-manager UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 01/28/2011 dmi.bios.vendor: Dell Inc. dmi.bios.version: A09 dmi.board.name: 05C67D dmi.board.vendor: Dell Inc. dmi.board.version: A00 dmi.chassis.type: 9 dmi.chassis.vendor: Dell Inc. dmi.modalias: dmi:bvnDellInc.:bvrA09:bd01/28/2011:svnDellInc.:pnLatitudeE5410:pvr0001:rvnDellInc.:rn05C67D:rvrA00:cvnDellInc.:ct9:cvr: dmi.product.name: Latitude E5410 dmi.product.version: 0001 dmi.sys.vendor: Dell Inc. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-power-manager/+bug/847001/+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
