I tested on an L322X with _F_HD display and A09 BIOS in UEFI mode. $ cat /proc/cmdline BOOT_IMAGE=/vmlinuz-3.11.0-14-generic root=/dev/mapper/ubuntu--vg-root ro splash quiet i915.disable_pch_pwm=0 vt.handoff=7
If I use i915.disable_pch_pwm=0 with the legacy OPROM enabled, I have to run "echo 0 > /sys/class/backlight/intel_backlight/brightness", after which the backlight keys work. If I use i915.disable_pch_pwm=1 with the legacy OPROM _disabled_, the backlight keys work without any additional work. If I use i915.disable_pch_pwm=0 with the legacy OPROM _disabled_, your test kernel fixes the backlight issue. (However, apparently Saucy's kernel causes really bad graphics corruption if the legacy OPROM is disabled, which is a separate issue.) And for kicks, i915.disable_pch_pwm=1 with the legacy OPROM disabled brings the system up with the backlight at its lowest setting. -- 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/1163720 Title: Brightness control broken on XPS13 and 3.8.0-16, 3.8.0-22 and 3.11.0-12 Status in The Linux Kernel: Incomplete Status in “linux” package in Ubuntu: Fix Released Status in “linux” source package in Precise: Fix Released Status in “linux” source package in Raring: In Progress Bug description: Since 3.8.0-16, the brightness control doesn’t work anymore. The popup is displayed, so the shortcut keys do work correctly, but it has no effect on the actual brightness of the screen. Switching back to 3.8.0-15 solves the issue. ProblemType: Bug DistroRelease: Ubuntu 13.04 Package: linux-image-3.8.0-16-generic 3.8.0-16.26 ProcVersionSignature: Ubuntu 3.8.0-16.26-generic 3.8.5 Uname: Linux 3.8.0-16-generic x86_64 ApportVersion: 2.9.2-0ubuntu5 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: coucouf 1837 F.... pulseaudio Date: Wed Apr 3 08:29:58 2013 DistributionChannelDescriptor: # This is a distribution channel descriptor # For more information see http://wiki.ubuntu.com/DistributionChannelDescriptor canonical-oem-somerville-precise-amd64-20120703-2 HibernationDevice: RESUME=UUID=e49e9eae-f16f-45bb-ad2c-b6da5c0c6f6d InstallationDate: Installed on 2013-03-23 (10 days ago) InstallationMedia: Ubuntu 12.04 "Precise" - Build amd64 LIVE Binary 20120703-15:08 MachineType: Dell Inc. Dell System XPS L322X MarkForUpload: True ProcEnviron: TERM=xterm PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=fr_FR.UTF-8 SHELL=/bin/bash ProcFB: 0 inteldrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.8.0-16-generic root=UUID=3f6858e1-d8f5-44c4-b8e9-5ab8b9639ba7 ro quiet splash vt.handoff=7 RelatedPackageVersions: linux-restricted-modules-3.8.0-16-generic N/A linux-backports-modules-3.8.0-16-generic N/A linux-firmware 1.104 SourcePackage: linux UpgradeStatus: Upgraded to raring on 2013-04-02 (0 days ago) dmi.bios.date: 01/22/2013 dmi.bios.vendor: Dell Inc. dmi.bios.version: A07 dmi.board.name: 0PJHXN dmi.board.vendor: Dell Inc. dmi.board.version: A00 dmi.chassis.type: 8 dmi.chassis.vendor: Dell Inc. dmi.chassis.version: 0.1 dmi.modalias: dmi:bvnDellInc.:bvrA07:bd01/22/2013:svnDellInc.:pnDellSystemXPSL322X:pvr:rvnDellInc.:rn0PJHXN:rvrA00:cvnDellInc.:ct8:cvr0.1: dmi.product.name: Dell System XPS L322X dmi.sys.vendor: Dell Inc. To manage notifications about this bug go to: https://bugs.launchpad.net/linux/+bug/1163720/+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