stack traces in dmesg on boot i915 related on macbook air

[Jeff Lane ]

Noticed stack traces in dmesg after booting Wily on a macbook air. See attached logs. Seems to be related to i915 chipset.

ProblemType: Bug
DistroRelease: Ubuntu 15.10
Package: linux-image-4.2.0-16-generic 4.2.0-16.19 [modified: boot/vmlinuz-4.2.0-16-generic]
ProcVersionSignature: Ubuntu 4.2.0-16.19-generic 4.2.3
Uname: Linux 4.2.0-16-generic x86_64
NonfreeKernelModules: wl
ApportVersion: 2.19.1-0ubuntu4
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: bladernr 2027 F.... pulseaudio
 /dev/snd/controlC1: bladernr 2027 F.... pulseaudio
CurrentDesktop: Unity
Date: Sun Nov 1 15:34:03 2015
HibernationDevice: RESUME=UUID=1ec334c0-b29f-454a-9668-0e6f5cc2d152
InstallationDate: Installed on 2015-10-21 (11 days ago)
InstallationMedia: Ubuntu 15.10 "Wily Werewolf" - Release amd64 (20151020)
MachineType: Apple Inc. MacBookAir6,1
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.2.0-16-generic.efi.signed root=UUID=36666d44-163a-4386-9871-83e8515efd90 ro quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-4.2.0-16-generic N/A
 linux-backports-modules-4.2.0-16-generic N/A
 linux-firmware 1.149
SourcePackage: linux
UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 06/05/2015
dmi.bios.vendor: Apple Inc.
dmi.bios.version: MBA61.88Z.0099.B19.1506050547
dmi.board.asset.tag: Base Board Asset Tag#
dmi.board.name: Mac-35C1E88140C3E6CF
dmi.board.vendor: Apple Inc.
dmi.board.version: MacBookAir6,1
dmi.chassis.type: 10
dmi.chassis.vendor: Apple Inc.
dmi.chassis.version: Mac-35C1E88140C3E6CF
dmi.modalias: dmi:bvnAppleInc.:bvrMBA61.88Z.0099.B19.1506050547:bd06/05/2015:svnAppleInc.:pnMacBookAir6,1:pvr1.0:rvnAppleInc.:rnMac-35C1E88140C3E6CF:rvrMacBookAir6,1:cvnAppleInc.:ct10:cvrMac-35C1E88140C3E6CF:
dmi.product.name: MacBookAir6,1
dmi.product.version: 1.0
dmi.sys.vendor: Apple Inc.

[Brad Figg (brad-figg)]

This change was made by a bot.

[Joseph Salisbury (jsalisbury)]

Did this issue start happening after an update/upgrade? Was there a kernel version where you were not having this particular problem? This will help determine if the problem you are seeing is the result of a regression, and when this regression was introduced. If this is a regression, we can perform a kernel bisect to identify the commit that introduced the problem.