Ubuntu
xserver-xorg-video-intel package

[I+N] Split screen after setting the monitors configuration to extended

Bug #1405325 reported by Anthony Wong on 2014-12-24

This bug affects 2 people

	Status	Importance	Assigned to
HWE Next	Invalid	High	Unassigned
Trusty	Fix Released	Undecided	Unassigned
xserver-xorg-video-intel (Ubuntu)	Invalid	High	Maarten Lankhorst
Trusty	Fix Released	High	Maarten Lankhorst

Bug Description

Steps:
1. Install trusty image and log in to system
2. Connect an external DP monitor.
3. Press the display hot key to change the monitors configuration

Actual result:
Split screen after set the monitors configuration to extended mode.

Expected result:
The video signal can be mirrored, extended, displayed on external or onboard only.

[Analysis from NVIDIA]
I tracked down the culprit to an Ubuntu patch applied to xf86-video-intel 2.99.910: patches/10-handle-rotated-slaves.diff. That patch is a cherry-pick of upstream commit a45b2ea11c15f35c36330ff27cb45854a29c2e2c. The Ubuntu version of the patch is significantly different from the upstream commit, so somebody must have done quite a bit of porting. Either they messed it up during porting, or they missed cherry-picking another upstream commit that fixes the problem.

It looks like what's happening is that the Intel driver is applying the RandR CRTC offset even though it's actually scanning out from a CRTC-sized private scanout buffer. Since it's a linear buffer, this shifts all of the lines over by however many pixels the CRTC offset is set to, wrapping lines around in the process.

See original description

Tags:

Revision history for this message

Anthony Wong (anthonywong) wrote on 2014-12-24:

screenshot of the issue Edit (1.6 MiB, image/jpeg)

Revision history for this message

Anthony Wong (anthonywong) wrote on 2014-12-24:

video showing the bug Edit (14.4 MiB, video/mp4)

summary:

- Split screen after setting the monitors configuration to extended
+ [I+N] Split screen after setting the monitors configuration to extended

Revision history for this message

Anthony Wong (anthonywong) wrote on 2014-12-24:

lspci Edit (8.8 KiB, text/plain)

description:	updated
description:	updated

Anthony Wong (anthonywong) on 2014-12-24

Changed in xserver-xorg-video-intel (Ubuntu):
importance:	Undecided → High
no longer affects:	xorg-server (Ubuntu)
Changed in hwe-next:
importance:	Undecided → High
status:	New → Triaged

Anthony Wong (anthonywong) on 2015-01-08

Changed in xserver-xorg-video-intel (Ubuntu):
assignee:	nobody → Maarten Lankhorst (mlankhorst)

Anthony Wong (anthonywong) on 2015-01-08

Changed in xserver-xorg-video-intel (Ubuntu Trusty):
assignee:	nobody → Maarten Lankhorst (mlankhorst)
importance:	Undecided → High

Revision history for this message

Maarten Lankhorst (mlankhorst) wrote on 2015-01-13:

patch Edit (1.2 KiB, text/plain)

Thanks, the analysis was completely correct. It looks like I missed changing a 0, 0, to sx, sy. Fixing that up makes things work again. :-)

Changed in xserver-xorg-video-intel (Ubuntu):
status:	New → Invalid
tags:	added: regression-update
tags:	added: trusty

Revision history for this message

Maarten Lankhorst (mlankhorst) wrote on 2015-01-13:

Can you test if the above patch fixes it?

Changed in xserver-xorg-video-intel (Ubuntu Trusty):
status:	New → Incomplete

Anthony Wong (anthonywong) on 2015-01-13

Changed in hwe-next:
status:	Triaged → Invalid

Revision history for this message

Anthony Wong (anthonywong) wrote on 2015-01-14:

Madper Xie (bbboson) wrote 1 hour ago:
The patch in works well. Both split screen and performance issue are fixed. (I tested both U2412Mb and U2713H.)

Revision history for this message

Chris J Arges (arges) wrote on 2015-01-14: Please test proposed package

Hello Anthony, or anyone else affected,

Accepted xserver-xorg-video-intel into trusty-proposed. The package will build now and be available at http://launchpad.net/ubuntu/+source/xserver-xorg-video-intel/2:2.99.910-0ubuntu1.4 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!

Changed in xserver-xorg-video-intel (Ubuntu Trusty):
status:	Incomplete → Fix Committed
tags:	added: verification-needed

Revision history for this message

Madper Xie (bbboson) wrote on 2015-01-16:

reproduce.png Edit (712.9 KiB, image/png)

I have verified the Proposed-package. It fixed the split-screen issue. Works good for me:

My test bed:
a ThinkPad t450 laptop with Nvidia Device 1347.

Reproduce:
before I install the proposed-package, the version is:
ii xserver-xorg-video-intel 2:2.99.910-0ubuntu1.3 amd64 X.Org X server -- Intel i8xx, i9xx display driver

The attached picture shows the problem

Verification:
after I install the proposed-package in Comment #7, I can't reproduce the same issue.

So I believe the issue is fixed by the new package.

tags:

added: verification-done
removed: verification-needed

Revision history for this message

Maarten Lankhorst (mlankhorst) wrote on 2015-01-19:

Same results here.

Revision history for this message

Launchpad Janitor (janitor) wrote on 2015-02-09:

#10

This bug was fixed in the package xserver-xorg-video-intel - 2:2.99.910-0ubuntu1.4

---------------
xserver-xorg-video-intel (2:2.99.910-0ubuntu1.4) trusty-proposed; urgency=medium

  [ Timo Aaltonen ]
  * sna-fix-gen8-blt.diff
    sna-tweak-alignment-constraints-on-gen8.diff
    sna-add-more-checks-and-asserts-for-blt.diff:
    - Fix GEN8 BLT with 4bit address. (LP: #1401788)

  [ Maarten Lankhorst ]
  * Fix regression with external displays on sna. (LP: #1405325)
  * 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 17:14:19 +0100

Changed in xserver-xorg-video-intel (Ubuntu Trusty):
status:	Fix Committed → Fix Released

Revision history for this message

Adam Conrad (adconrad) wrote on 2015-02-09: Update Released

#11

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.