Hello David, I'm not sure to what extent this tweak will affect the battery life.
I tried to measure the power consumption today, with and without these two options individually. But I can't tell the real difference between them, the reading will jump within a certain range. Maybe the euipement we have here (IDRC CP-268) is not up for this job (it's being tested with adapter connected), or maybe I don't have enough knowledge for using it. Test enviroment: Laptop with battery removed, Wifi / Bluetooth turned off, backlight tuned down to the lowest level. Power comsumption (total wattage) measured by IDRC CP-268, with laptop adapter connected to it. Test result: Wattage jumps aroung 11.31 ~ 11.38 in these three secnerios. If there is any difference, it looks like it's less than 0.1 watt, but again, I'm not very confident about this. If you need a much more precise test report, I think I can imporve it by choosing a SSD laptop, with all extra modules removed. And sample the reading every 10 minute to get an average. (Or do you have any recommended testing technique or software?) Also, there is a simliar bug reported by QA before: https://bugs.launchpad.net/somerville/+bug/1067672 >From here, maybe it indicates that the "options snd-hda-intel >power_save_controller=N" could be an acceptable fix. -- 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/1383997 Title: [Dell Vostro 5470] No HDMI audio with 14.04 Status in HWE Next Project: Triaged Status in “linux” package in Ubuntu: Confirmed Bug description: CID: 201307-14037 Dell Vostro 5470 There is no HDMI audio output option available when you connect the HDMI monitor (with speaker) to this system. Verified with cold plug, still no luck. However, HDMI audio could be detected with cold plug on 12.04.4 (3.11 kernel) stock Ubuntu, tested with LiveUSB Alsa-info: http://www.alsa-project.org/db/?f=8e5ccdaae7aa4b3a05862385b902f824be65f0bd ProblemType: Bug DistroRelease: Ubuntu 14.04 Package: linux-image-3.13.0-37-generic 3.13.0-37.64 ProcVersionSignature: Ubuntu 3.13.0-37.64-generic 3.13.11.7 Uname: Linux 3.13.0-37-generic x86_64 ApportVersion: 2.14.1-0ubuntu3.5 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: ubuntu 1589 F.... pulseaudio /dev/snd/controlC1: ubuntu 1589 F.... pulseaudio CRDA: country TW: (2402 - 2472 @ 40), (3, 27) (5270 - 5330 @ 40), (3, 17), DFS (5735 - 5815 @ 40), (3, 30) CurrentDesktop: Unity Date: Tue Oct 21 22:44:45 2014 HibernationDevice: RESUME=UUID=420e55c0-b179-44d6-93d7-82393cdeec68 InstallationDate: Installed on 2014-10-21 (0 days ago) InstallationMedia: Ubuntu 14.04.1 LTS "Trusty Tahr" - Release amd64 (20140722.2) MachineType: Dell Inc. Vostro 5470 ProcFB: 0 inteldrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-37-generic.efi.signed root=UUID=a975e1af-1e52-4f17-8e69-190b4dc36b48 ro quiet splash RelatedPackageVersions: linux-restricted-modules-3.13.0-37-generic N/A linux-backports-modules-3.13.0-37-generic N/A linux-firmware 1.127.7 SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 08/23/2013 dmi.bios.vendor: Dell Inc. dmi.bios.version: A01 dmi.board.asset.tag: Base Board Asset Tag dmi.board.name: White Tip Mountain dmi.board.vendor: Intel Corp. dmi.board.version: FAB3 dmi.chassis.asset.tag: Asset Tag dmi.chassis.type: 9 dmi.chassis.vendor: Intel Corporation dmi.chassis.version: 0.1 dmi.modalias: dmi:bvnDellInc.:bvrA01:bd08/23/2013:svnDellInc.:pnVostro5470:pvr:rvnIntelCorp.:rnWhiteTipMountain:rvrFAB3:cvnIntelCorporation:ct9:cvr0.1: dmi.product.name: Vostro 5470 dmi.sys.vendor: Dell Inc. To manage notifications about this bug go to: https://bugs.launchpad.net/hwe-next/+bug/1383997/+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
