Horrible noise via DisplayPort [regression]

[Andreas Schildbach]

This issue has been present and fixed two years ago and with Trusty Tahr it re-appeared:

When logging in and my display is extended to two monitors, and also when the screen blanks, I get 3-5 seconds of horrible noise via DisplayPort audio out.

The noise is loud enough to damage ears and loudspeakers, if volume has been set to a normal listening level.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: xserver-xorg-video-intel 2:2.99.910-0ubuntu1
ProcVersionSignature: Ubuntu 3.13.0-18.38-generic 3.13.6
Uname: Linux 3.13.0-18-generic x86_64
.tmp.unity.support.test.0:

ApportVersion: 2.13.3-0ubuntu1
Architecture: amd64
CompizPlugins: [core,composite,opengl,compiztoolbox,decor,vpswitch,snap,mousepoll,resize,place,move,wall,grid,regex,imgpng,session,gnomecompat,animation,fade,unitymtgrabhandles,workarounds,scale,expo,ezoom,unityshell]
CompositorRunning: compiz
CompositorUnredirectDriverBlacklist: '(nouveau|Intel).*Mesa 8.0'
CompositorUnredirectFSW: true
CurrentDesktop: Unity
Date: Sun Mar 23 10:18:08 2014
DistUpgraded: 2014-01-03 23:25:11,434 DEBUG enabling apt cron job
DistroCodename: trusty
DistroVariant: ubuntu
ExtraDebuggingInterest: Yes
GraphicsCard:
 Intel Corporation Core Processor Integrated Graphics Controller [8086:0046] (rev 02) (prog-if 00 [VGA controller])
   Subsystem: Lenovo Device [17aa:21c1]
InstallationDate: Installed on 2011-08-05 (960 days ago)
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Alpha amd64 (20110803.1)
MachineType: LENOVO 29123AG
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-18-generic root=UUID=b9fb2d9e-d248-4294-bd6b-9abe27dfcea4 ro quiet splash
SourcePackage: xserver-xorg-video-intel
UpgradeStatus: Upgraded to trusty on 2014-01-03 (78 days ago)
dmi.bios.date: 10/11/2012
dmi.bios.vendor: LENOVO
dmi.bios.version: 6UET70WW (1.50 )
dmi.board.name: 29123AG
dmi.board.vendor: LENOVO
dmi.board.version: Not Available
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvr6UET70WW(1.50):bd10/11/2012:svnLENOVO:pn29123AG:pvrThinkPadT410s:rvnLENOVO:rn29123AG:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 29123AG
dmi.product.version: ThinkPad T410s
dmi.sys.vendor: LENOVO
version.compiz: compiz 1:0.9.11+14.04.20140320.1-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.52-1
version.libgl1-mesa-dri: libgl1-mesa-dri 10.1.0-1ubuntu1
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 10.1.0-1ubuntu1
version.xserver-xorg-core: xserver-xorg-core 2:1.15.0-1ubuntu7
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.8.2-1ubuntu2
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.3.0-1ubuntu3
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.910-0ubuntu1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.10-1ubuntu2
xserver.bootTime: Sun Mar 23 10:09:13 2014
xserver.configfile: default
xserver.errors:
 N-Trig Pen stylus: Invalid type 'cursor' for this device.
 N-Trig Pen stylus: Invalid type 'touch' for this device.
xserver.logfile: /var/log/Xorg.0.log
xserver.outputs:
 product id 16438
 vendor LEN
xserver.version: 2:1.15.0-1ubuntu7

[Andreas Schildbach (schildbach)]

I cannot test this, because I moved to Utopic and Vivid. Both kernels have the same problem. I think this test is as good as the one you're proposing and the status of this ticket can be moved back to 'new'.

[penalvch (penalvch)]

Andreas Schildbach, any change via http://cdimage.ubuntu.com/daily-live/current/ ?

[Andreas Schildbach (schildbach)]

Yes, I just reproduced it using the current live CD.

[penalvch (penalvch)]

Andreas Schildbach, 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.

[Andreas Schildbach (schildbach)]

The bug also exists on upstream kernel 4.3-rc3.

[penalvch (penalvch)]

Andreas Schildbach, could you please advise what was the most recent release this problem did not occur in?

[Andreas Schildbach (schildbach)]

I just tried Ubuntu 12.04.5 LTS (kernel 3.13.0-45-generic) and the problem exists.

Where can I download images for the (now EOL'ed) Q, R and S releases?

[Andreas Schildbach (schildbach)]

I just found old-releases.ubuntu.com.

Ubuntu 13.10 (kernel 3.11.0-12-generic) is the last version that doesn't have this bug!

[Andreas Schildbach (schildbach)]

To sum it up:

3.8.0-19-generic: could not enable HDMI audio, though I believe it was possible somehow
3.11.0-12-generic: WORKS FINE
3.13.0-18-generic: BUG
3.13.0-45-generic: BUG
3.19.0-28-generic: BUG
4.3-rc3: BUG

[penalvch (penalvch)]

Andreas Schildbach, the next step is to fully commit bisect from kernel 3.11 to 3.13 in order to identify the last good kernel commit, followed immediately by the first bad one. This will allow for a more expedited analysis of the root cause of your issue. Could you please do this following https://wiki.ubuntu.com/Kernel/KernelBisection ?

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

[Andreas Schildbach (schildbach)]

Christopher, before I take this effort I have two questions:

1) Are you sure this is a regression in the kernel itself? It could also be a bug in another package (e.g. xserver-xorg-video-intel), right?

2) Do kernels in the 3.11.0-3.13.0 range work in combination with a modern 15.04 distribution? Unfortunately I cannot downgrade back to 13.10/14.04 if this would be required for testing old kernels.

[penalvch (penalvch)]

Andreas Schildbach, you have a clear, and obvious kernel regression as per your previous comments. If this was a bug in a different package, then keeping the linux kernel version the same, but changing the other package would cause the change in functionality.

One is free to test as old a kernel as one desires, given the support for the hardware is in place.

[Andreas Schildbach (schildbach)]

Christopher, be aware that up to now I mainly tested by booting live CDs, so of course also all other packages changed as well.

But I just tested two more mainline kernels on my 15.04 system (so without changing any of the other packages):

3.12.48-0131248-generic: WORKS FINE. This is the last mainline kernel that doesn't exhibit the bug.
3.13.0-031300rc1-generic: BUG. This is the first mainline kernel that has the bug.

Guess I'll now start kernel bisecting between these two versions.

[Andreas Schildbach (schildbach)]

Christopher, I tried building the kernel from git source (git://kernel.ubuntu.com/ubuntu/ubuntu-trusty.git) but it always boots up without the necessary drivers. Only with "dummy" sound and just a basic screen resolution without support for dual screen etc. I followed: https://wiki.ubuntu.com/Kernel/BuildYourOwnKernel and tried using "fakeroot debian/rules updateconfigs". How can I make it so the build uses the same config like all Ubuntu kernels?

[penalvch (penalvch)]

Andreas Schildbach, binaries are available for prior versions as outlined in https://wiki.ubuntu.com/Kernel/KernelBisection .

[Andreas Schildbach (schildbach)]

I bisected the bug down to this commit:

commit fdbc3b1f639bb2cbfb32c612b2699e0ba373317d
Author: Jani Nikula <email address hidden>
Date: Tue Nov 12 17:10:13 2013 +0200

    drm/i915/dp: set sink to power down mode on dp disable

FWIW, here is the full bisect log:

$ git bisect log
# bad: [52cd2b0342665668e7d3806d4a0b2ff837651690] UBUNTU: Ubuntu-3.13.0-0.2
# good: [4f57e47bab90529e40d11878ba8b5f429cfa1d95] UBUNTU: Ubuntu-3.12.0-8.16
git bisect start 'Ubuntu-3.13.0-0.2' 'Ubuntu-3.12.0-8.16'
# good: [5e01dc7b26d9f24f39abace5da98ccbd6a5ceb52] Linux 3.12
git bisect good 5e01dc7b26d9f24f39abace5da98ccbd6a5ceb52
# good: [5cbb3d216e2041700231bcfc383ee5f8b7fc8b74] Merge branch 'akpm' (patches from Andrew Morton)
git bisect good 5cbb3d216e2041700231bcfc383ee5f8b7fc8b74
# good: [d8fe4acc88da8fbbe360b6592c9d0abbb85117dc] Merge branch 'akpm' (patch-bomb from Andrew Morton)
git bisect good d8fe4acc88da8fbbe360b6592c9d0abbb85117dc
# good: [73d75ba99e3bdd627275afd3fe48cc933723084b] Merge tag 'sound-fix-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
git bisect good 73d75ba99e3bdd627275afd3fe48cc933723084b
# good: [e6d69a60b77a6ea8d5f9d41765c7571bb8d45531] Merge branch 'next' of git://git.infradead.org/users/vkoul/slave-dma
git bisect good e6d69a60b77a6ea8d5f9d41765c7571bb8d45531
# good: [d2c2ad54c485e7ebca5c0b7e4a7b2c56103fda38] Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
git bisect good d2c2ad54c485e7ebca5c0b7e4a7b2c56103fda38
# bad: [26b265cd29dde56bf0901c421eabc7ae815f38c4] Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
git bisect bad 26b265cd29dde56bf0901c421eabc7ae815f38c4
# bad: [aecde27c4fc4939f7c16ae13645f896438190567] Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux
git bisect bad aecde27c4fc4939f7c16ae13645f896438190567
# good: [b0e3636f656c98bdeded5aaa78601e3256b18d6d] Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending
git bisect good b0e3636f656c98bdeded5aaa78601e3256b18d6d
# bad: [cf969677945e6e19810d616873617320da002e32] Merge tag 'drm-intel-fixes-2013-11-20' of git://people.freedesktop.org/~danvet/drm-intel into drm-fixes
git bisect bad cf969677945e6e19810d616873617320da002e32
# good: [7272c9d2286525d4c6bce788243cf2b6f306d15c] drm/radeon: hook up backlight functions for CI and KV family.
git bisect good 7272c9d2286525d4c6bce788243cf2b6f306d15c
# bad: [7a495cfd9b5f82c40608f26fe523dc9e8533dc14] drm/i915/tv: add ->get_config callback
git bisect bad 7a495cfd9b5f82c40608f26fe523dc9e8533dc14
# bad: [f69e515699d8e9b1c25dcfe1c4c6f435087495d2] i915: Use 120MHz LVDS SSC clock for gen5/gen6/gen7
git bisect bad f69e515699d8e9b1c25dcfe1c4c6f435087495d2
# bad: [7bd40c16ccb2cb6877dd00b0e66249c171e6fa43] x86/early quirk: use gen6 stolen detection for VLV
git bisect bad 7bd40c16ccb2cb6877dd00b0e66249c171e6fa43
# bad: [fdbc3b1f639bb2cbfb32c612b2699e0ba373317d] drm/i915/dp: set sink to power down mode on dp disable
git bisect bad fdbc3b1f639bb2cbfb32c612b2699e0ba373317d
# first bad commit: [fdbc3b1f639bb2cbfb32c612b2699e0ba373317d] drm/i915/dp: set sink to power down mode on dp disable

[penalvch (penalvch)]

Andreas Schildbach, the issue you are reporting is an upstream one. Could you please report this problem following the instructions verbatim at https://wiki.ubuntu.com/Bugs/Upstream/kernel to the appropriate mailing list (intel-gfx CC Jani Nikula and Todd Previte)?

Please provide a direct URL to your e-mail to the mailing list once you have made it so that it may be tracked via http://vger.kernel.org/vger-lists.html . It can take a day for the new e-mail to show up in the respective archive.

Thank you for your understanding.

[Andreas Schildbach (schildbach)]

According to your linked instructions, the intel graphics teams does not seem to use a mailing list for bug reports. Instead, I reported it in their bugtracker:

https://bugs.freedesktop.org/show_bug.cgi?id=92237

[penalvch (penalvch)]

Andreas Schildbach, while I did advise in my comment:
>"intel-gfx CC Jani Nikula and Todd Previte"

because there is no guarantee either Jani or Todd are looking at bugzilla, or accept reports there, I see why this confusion occurred. Hence, I've clarified the wiki so this shouldn't be a problem in the future.

[Andreas Schildbach (schildbach)]

I cc'd both of them on the ticket, so they should notice.

Anyway, I just tried mailing <email address hidden> but that address doesn't exist:

<email address hidden>: host vger.kernel.org[209.132.180.67] said: 554
    5.0.0 Hi [78.46.152.204], unresolvable address:
    <email address hidden>; nosuchuser; <email address hidden> (in
    reply to RCPT TO command)

Also, it's not listed on http://vger.kernel.org/vger-lists.html so I assume there is some mistake with the mailing list address.

[penalvch (penalvch)]

Andreas Schildbach, the mailing list address as per the wiki references to http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/MAINTAINERS which states :
<email address hidden>

[Andreas Schildbach (schildbach)]

Thanks, I now posted to the right mailing list:
http://lists.freedesktop.org/archives/intel-gfx/2015-October/077193.html

[penalvch (penalvch)]

Andreas Schildbach, unfortunately you didn't follow the Kernel.org format advised in the wiki, which provides a lot of helpful information. For example, posting lspci by itself is largely useless without the switches.

[Andreas Schildbach (schildbach)]

Sorry, too many instructions and too many dead ends in those. I just appended the info that I missed out.