External monitors are not detected

[Jose C. Massón]

$ cat /proc/version_signature
Ubuntu 4.2.0-18.22-generic 4.2.3

ProblemType: Bug
DistroRelease: Ubuntu 15.10
Package: linux-image-4.2.0-18-generic 4.2.0-18.22
ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
Uname: Linux 4.2.0-18-generic x86_64
NonfreeKernelModules: wl
ApportVersion: 2.19.1-0ubuntu4
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: jose 2139 F.... pulseaudio
CurrentDesktop: Unity
Date: Tue Nov 17 10:33:39 2015
HibernationDevice: RESUME=UUID=c1967c1f-cf6a-49ac-95bf-5da28a8e0929
InstallationDate: Installed on 2015-11-16 (1 days ago)
InstallationMedia: Ubuntu 15.10 "Wily Werewolf" - Release amd64 (20151021)
MachineType: Apple Inc. MacBookPro8,1
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/@/boot/vmlinuz-4.2.0-18-generic.efi.signed root=UUID=65bd7fe5-9d35-435c-8064-5be1d902b6bb ro rootflags=subvol=@ quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-4.2.0-18-generic N/A
 linux-backports-modules-4.2.0-18-generic N/A
 linux-firmware 1.149.2
SourcePackage: linux
UdevLog: Error: [Errno 2] No existe el archivo o el directorio: '/var/log/udev'
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 06/08/15
dmi.bios.vendor: Apple Inc.
dmi.bios.version: MBP81.88Z.0047.B2A.1506082203
dmi.board.asset.tag: Base Board Asset Tag#
dmi.board.name: Mac-94245B3640C91C81
dmi.board.vendor: Apple Inc.
dmi.board.version: MacBookPro8,1
dmi.chassis.type: 10
dmi.chassis.vendor: Apple Inc.
dmi.chassis.version: Mac-94245B3640C91C81
dmi.modalias: dmi:bvnAppleInc.:bvrMBP81.88Z.0047.B2A.1506082203:bd06/08/15:svnAppleInc.:pnMacBookPro8,1:pvr1.0:rvnAppleInc.:rnMac-94245B3640C91C81:rvrMacBookPro8,1:cvnAppleInc.:ct10:cvrMac-94245B3640C91C81:
dmi.product.name: MacBookPro8,1
dmi.product.version: 1.0
dmi.sys.vendor: Apple Inc.

[Brad Figg (brad-figg)]

This change was made by a bot.

[penalvch (penalvch)]

Jose, 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, and Y are the first two numbers of the kernel version, and Z is the release candidate number if it exists.

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.

[Jose C. Massón (jose-masson)]

I tested with the following kernels:

linux-image-4.2.1-040201-generic_4.2.1-040201.201509211431_amd64.deb
linux-image-4.2.2-040202-generic_4.2.2-040202.201509291435_amd64.deb
linux-image-4.2.3-040203-generic_4.2.3-040203.201510030832_amd64.deb
linux-image-4.2.4-040204-generic_4.2.4-040204.201510261009_amd64.deb
linux-image-4.2.5-040205-generic_4.2.5-040205.201510270124_amd64.deb
linux-image-4.2.6-040206-generic_4.2.6-040206.201511091832_amd64.deb
linux-image-4.3.0-040300-generic_4.3.0-040300.201511020949_amd64.deb

And only works whit:
linux-image-4.3.0-040300-generic_4.3.0-040300.201511020949_amd64.deb

[penalvch (penalvch)]

Jose, the next step is to fully reverse commit bisect from kernel 4.2.6 to 4.3 in order to identify the last bad commit, followed immediately by the first good one. Once this commit has been identified, then it may be reviewed as a candidate for backporting into your release. Could you please do this following https://wiki.ubuntu.com/Kernel/KernelBisection#How_do_I_reverse_bisect_the_upstream_kernel.3F ?

Please note, finding adjacent kernel versions is not fully commit bisecting.

Thank you for your understanding.

Helpful bug reporting tips:
https://wiki.ubuntu.com/ReportingBugs

[Jose C. Massón (jose-masson)]

Christopher, I tested now with the following kernels (between 4.2.6 and 4.3.0)

linux-image-4.3.0-040300-generic_4.3.0-040300.201511020949_amd64.deb
linux-image-4.3.0-040300rc1-generic_4.3.0-040300rc1.201509160642_amd64.deb
linux-image-4.3.0-040300rc2-generic_4.3.0-040300rc2.201509201830_amd64.deb
linux-image-4.3.0-040300rc3-generic_4.3.0-040300rc3.201509271225_amd64.deb
linux-image-4.3.0-040300rc4-generic_4.3.0-040300rc4.201510041330_amd64.deb
linux-image-4.3.0-040300rc5-generic_4.3.0-040300rc5.201510111530_amd64.deb
linux-image-4.3.0-040300rc6-generic_4.3.0-040300rc6.201510182030_amd64.deb
linux-image-4.3.0-040300rc7-generic_4.3.0-040300rc7.201510260712_amd64.deb

And works fine with everyone.

So installing the kernels published in http://kernel.ubuntu.com/~kernel-ppa/mainline/?C=N;O=D from v4.2-wily to v4.3-wily only works fine with kernels 4.3*

Tell me if you need I should test with many other versions.

[Jose C. Massón (jose-masson)]

Christopher, do you need more feedback? What can I do?

[penalvch (penalvch)]

Jose, this report is awaiting your commit bisect as outlined in https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1517048/comments/5 .

[Launchpad Janitor (janitor)]

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]