No screen backlight after suspending and resuming on Macbook 4.1

[Arvid Krein]

Hardware:
Macbook-4.1 2008
Graphics: Intel® 965GM

Software:
ubuntu 15.10

tested kernels:
4.3.0-999-generic
4.1.0-040100rc2-genereic

expected:
After performing a suspend and resuming the screen back light is turned back on.

observed:
When trying to suspend and wake up after, the device comes back on but the screen back light stays off. If shined on with an external light source the content of the screen is still readable.

steps to reproduce:
1. suspend (via pm-suspend, user interface, or automatic behavior
2. attempt to wake up
3. observe the back light of the screen

ProblemType: Bug
DistroRelease: Ubuntu 15.10
Package: xorg 1:7.7+7ubuntu4
Uname: Linux 4.3.0-999-generic x86_64
.tmp.unity.support.test.0:

ApportVersion: 2.19.1-0ubuntu3
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: compiz
CompositorUnredirectDriverBlacklist: '(nouveau|Intel).*Mesa 8.0'
CompositorUnredirectFSW: true
CurrentDesktop: Unity
Date: Tue Oct 27 19:35:49 2015
DistUpgraded: 2015-10-25 04:06:39,623 DEBUG enabling apt cron job
DistroCodename: wily
DistroVariant: ubuntu
DkmsStatus: webcamstudio, 0.73, 4.2.0-16-generic, x86_64: installed
DpkgLog:

ExtraDebuggingInterest: Yes
GraphicsCard:
 Intel Corporation Mobile GM965/GL960 Integrated Graphics Controller (primary) [8086:2a02] (rev 03) (prog-if 00 [VGA controller])
   Subsystem: Apple Inc. Device [106b:00a1]
   Subsystem: Apple Inc. Device [106b:00a1]
InstallationDate: Installed on 2015-08-12 (76 days ago)
InstallationMedia: Ubuntu 15.04 "Vivid Vervet" - Release amd64 (20150422)
MachineType: Apple Inc. MacBook4,1
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.3.0-999-generic root=UUID=c4a2c5bc-c7c6-4887-a1e1-74ab339c4c7d ro acpi_osi=Linux acpi_baclight=vendor
SourcePackage: xorg
Symptom: display
UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
UpgradeStatus: Upgraded to wily on 2015-10-25 (2 days ago)
dmi.bios.date: 02/09/08
dmi.bios.vendor: Apple Inc.
dmi.bios.version: MB41.88Z.00C1.B00.0802091535
dmi.board.asset.tag: Base Board Asset Tag
dmi.board.name: Mac-F22788A9
dmi.board.vendor: Apple Inc.
dmi.board.version: PVT
dmi.chassis.asset.tag: Asset Tag#
dmi.chassis.type: 2
dmi.chassis.vendor: Apple Inc.
dmi.chassis.version: Mac-F22788A9
dmi.modalias: dmi:bvnAppleInc.:bvrMB41.88Z.00C1.B00.0802091535:bd02/09/08:svnAppleInc.:pnMacBook4,1:pvr1.0:rvnAppleInc.:rnMac-F22788A9:rvrPVT:cvnAppleInc.:ct2:cvrMac-F22788A9:
dmi.product.name: MacBook4,1
dmi.product.version: 1.0
dmi.sys.vendor: Apple Inc.
version.compiz: compiz 1:0.9.12.2+15.10.20151015-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.64-1
version.libgl1-mesa-dri: libgl1-mesa-dri 11.0.2-1ubuntu4
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 11.0.2-1ubuntu4
version.xserver-xorg-core: xserver-xorg-core 2:1.17.2-1ubuntu9
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.9.2-1ubuntu1
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.5.0+git20150819-0ubuntu1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20150808-0ubuntu4
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.11-1ubuntu3
xserver.bootTime: Sun Mar 24 12:22:50 2024
xserver.configfile: default
xserver.errors:

xserver.logfile: /var/log/Xorg.0.log
xserver.outputs:
 product id 5156
 vendor AUO
xserver.version: 2:1.17.2-1ubuntu9

[penalvch (penalvch)]

Arvind Krein, thank you for reporting this and helping make Ubuntu better.

Could you please test the latest upstream kernel available from the very top line at the top of the page from http://kernel.ubuntu.com/~kernel-ppa/mainline/?C=N;O=D (the release names are irrelevant for testing, and please do not test the daily folder)? Install instructions are available at https://wiki.ubuntu.com/Kernel/MainlineBuilds . This will allow additional upstream developers to examine the issue.

If the latest kernel did not allow you to test to the issue (ex. you couldn't boot into the OS) please make a comment in your report about this, and continue to test the next most recent kernel version until you can test to the issue. Once you've tested the upstream kernel, please comment on which kernel version specifically you tested. If this issue is fixed in the mainline kernel, please add the following tags by clicking on the yellow circle with a black pencil icon, next to the word Tags, located at the bottom of the report description:
kernel-fixed-upstream
kernel-fixed-upstream-X.Y-rcZ

Where X, Y, and Z are numbers corresponding to the kernel version.

If the mainline kernel does not fix the issue, please add the following tags:
kernel-bug-exists-upstream
kernel-bug-exists-upstream-X.Y-rcZ

Please note, an error to install the kernel does not fit the criteria of kernel-bug-exists-upstream.

Once testing of the latest upstream kernel is complete, please mark this report's Status as Confirmed. Please let us know your results.

Thank you for your understanding.

[Arvid Krein (arvid2000)]

Okay, I figured I forgot to reserve an EFI partition, what might have caused the behaviour. I don't know that much about technical stuff but it seems plausible to me, that if the running Ubuntu on a mac usually requires an EFI partition and there is none provided that can lead to all sorts of errors especially in hardware control. I reinstalled Ubuntu with a proper EFI partition and now everything is working smoothly. I guess the bug would be invalid then am I right? I am new to Launchpad so I am not quite sure, what I am supposed to do.

[penalvch (penalvch)]

Arvid Krein, this bug report is being closed due to your last comment https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1510668/comments/3 regarding you didn't reserve an EFI partition. For future reference you can manage the status of your own bugs by clicking on the current status in the yellow line and then choosing a new status in the revealed drop down box. You can learn more about bug statuses at https://wiki.ubuntu.com/Bugs/Status. Thank you again for taking the time to report this bug and helping to make Ubuntu better. Please submit any future bugs you may find.