Disable DRI3

[Timo Aaltonen]

[Impact]
from the upstream commit:

"The external libraries, both in git, and especially shipping already
    enabled in distributions, are buggy and lead to server crashes and
    lockups. Caveat emptor."

so disable it by default in vivid and utopic.

[Test case]
grep DRI3 /var/log/Xorg.0.log
should not return anything

[Regression potential]
none

[Launchpad Janitor (janitor)]

This bug was fixed in the package xserver-xorg-video-intel - 2:2.99.916+git20141119-1~exp1ubuntu1

---------------
xserver-xorg-video-intel (2:2.99.916+git20141119-1~exp1ubuntu1) vivid; urgency=medium

  * Merge from debian experimental (LP: #1401784, #1401788)
  * Drop upstream patches.

xserver-xorg-video-intel (2:2.99.916+git20141119-1~exp1) experimental; urgency=medium

  * New upstream snapshot.

xserver-xorg-video-intel (2:2.99.916-1~exp1) experimental; urgency=medium

  [ Vincent Cheng ]
  * New upstream prerelease 2.99.916.
    - sna: Add the current CRTC mode last (Closes: #750605)
  * Update debian/copyright. (Closes: #730643)
  * Revert to source format 1.0.

  [ Laurent Bigonville ]
  * debian/xserver-xorg-video-intel.maintscript: Explicitly remove
    i915-kms.conf on upgrade. (Closes: #713340)
 -- Timo Aaltonen <email address hidden> Fri, 12 Dec 2014 09:24:52 +0200

[Chris J Arges (arges)]

Timo,
Can you fill out the SRU template to explain the fix, if you'd like these accepted.
Thanks,

[Chris J Arges (arges)]

Hello Timo, or anyone else affected,

Accepted xserver-xorg-video-intel into utopic-proposed. The package will build now and be available at http://launchpad.net/ubuntu/+source/xserver-xorg-video-intel/2:2.99.914-1~exp1ubuntu4.2 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, and change the tag from verification-needed to verification-done. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

[Launchpad Janitor (janitor)]

This bug was fixed in the package xserver-xorg-video-intel - 2:2.99.914-1~exp1ubuntu4.2

---------------
xserver-xorg-video-intel (2:2.99.914-1~exp1ubuntu4.2) utopic-proposed; urgency=medium

  [ Timo Aaltonen ]
  * Added patches:
    - disable-dri3.diff: Disable DRI3. (LP: #1401784)
    - sna-fix-gen8-blt.diff,
      sna-add-more-checks-and-asserts-for-blt.diff,
      sna-tweak-alignment-constraints-on-gen8.diff:
      Fix GEN8 BLT with 4bit address. (LP: #1401788)
  [ Maarten Lankhorst ]
  * Fix rotating external display with optimus results in corruption.
    - fix-sna-external-slave-rotation.patch (LP: #1410238)
 -- Maarten Lankhorst <email address hidden> Tue, 13 Jan 2015 17:16:49 +0100

[Scott Kitterman (kitterman)]

The verification of the Stable Release Update for xserver-xorg-video-intel has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.

[Alanwww1 (alanwww1)]

Can anyone help how to re-enable DRI3 for testing purposes. On Fedora it is working quite well, eliminating tearing for my plasma desktop experience.

Is there a xorg.conf option I can use, or what packages has to be re-compiled with DRI3 ? What is the configuration option to make the driver use DRI3 by default ?

Thank you for the help in advanced !

[Alanwww1 (alanwww1)]

Just for anyone who wants to turn DR3 back, here is the solution I found:

- You need to have a DRI3 enabled xserver-xorg-video-intel driver. You can get one from the xorg-edgers ppa. I just downloaded the deb file that suits for my Ubuntu architecture from here: https://launchpad.net/~xorg-edgers/+archive/ubuntu/ppa/+packages?field.name_filter=&field.status_filter=published&field.series_filter=vivid

After that just do
sudo dpkg -i ./name_of_the_debfile

- xorg configuration needs adjustments. Just do
sudo vi /etc/X11/xorg.conf

and insert:

Section "Module"
        Load "dri3"
EndSection

Section "Device"
  Identifier "Intel"
  Option "DRI" "3"
EndSection

Now everything runs much smoother, without a sign of tearing.

[Alanwww1 (alanwww1)]

Any way of re-enable DRI3 without a custom driver to install ?