Touchscreen input clicks in the wrong place with dual-monitor setup

[David]

I have a touchscreen ultrabook (Samsung Ativ Book 9 Pro)

With a dual-monitor setup, touchscreen inputs are scaled to the whole desktop region rather than just the touchscreen display.

For example, with two displays (laptop on the left), touching the right half of the laptop's touch screen registers as a click on the touchless monitor. I expected the click to register where I touched the touchscreen.

ProblemType: Bug
DistroRelease: Ubuntu 15.10
Package: xorg 1:7.7+7ubuntu4
ProcVersionSignature: Ubuntu 4.2.0-23.28-generic 4.2.6
Uname: Linux 4.2.0-23-generic x86_64
.tmp.unity.support.test.0:

ApportVersion: 2.19.1-0ubuntu5
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: compiz
CompositorUnredirectDriverBlacklist: '(nouveau|Intel).*Mesa 8.0'
CompositorUnredirectFSW: true
CurrentDesktop: Unity
Date: Tue Jan 12 10:24:53 2016
DistUpgraded: Fresh install
DistroCodename: wily
DistroVariant: ubuntu
ExtraDebuggingInterest: Yes
GraphicsCard:
 Intel Corporation Device [8086:191b] (rev 06) (prog-if 00 [VGA controller])
   Subsystem: Samsung Electronics Co Ltd Device [144d:c12b]
   Subsystem: Samsung Electronics Co Ltd Device [144d:c12b]
InstallationDate: Installed on 2015-12-22 (20 days ago)
InstallationMedia: Ubuntu 15.10 "Wily Werewolf" - Release amd64 (20151021)
MachineType: SAMSUNG ELECTRONICS CO., LTD. 940Z5L
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-23-generic.efi.signed root=UUID=24c27814-5135-4a80-9ce1-b932e2513949 ro quiet splash vt.handoff=7
SourcePackage: xorg
Symptom: display
UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 10/20/2015
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: P04AFC.084.151020.SH
dmi.board.asset.tag: No Asset Tag
dmi.board.name: NP940Z5L-X01US
dmi.board.vendor: SAMSUNG ELECTRONICS CO., LTD.
dmi.board.version: SGL8554A1H-C01-G001-S0001+10.0.10240
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 9
dmi.chassis.vendor: SAMSUNG ELECTRONICS CO., LTD.
dmi.chassis.version: N/A
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrP04AFC.084.151020.SH:bd10/20/2015:svnSAMSUNGELECTRONICSCO.,LTD.:pn940Z5L:pvrP04AFC:rvnSAMSUNGELECTRONICSCO.,LTD.:rnNP940Z5L-X01US:rvrSGL8554A1H-C01-G001-S0001+10.0.10240:cvnSAMSUNGELECTRONICSCO.,LTD.:ct9:cvrN/A:
dmi.product.name: 940Z5L
dmi.product.version: P04AFC
dmi.sys.vendor: SAMSUNG ELECTRONICS CO., LTD.
version.compiz: compiz 1:0.9.12.2+15.10.20151015-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.64-1
version.libgl1-mesa-dri: libgl1-mesa-dri 11.0.2-1ubuntu4
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 11.0.2-1ubuntu4
version.xserver-xorg-core: xserver-xorg-core 2:1.17.2-1ubuntu9.1
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.9.2-1ubuntu1
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.5.0+git20150819-0ubuntu1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20150808-0ubuntu4
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.11-1ubuntu3
xserver.bootTime: Tue Jan 12 14:42:39 2016
xserver.configfile: default
xserver.errors:

xserver.logfile: /var/log/Xorg.0.log
xserver.outputs:
 product id 16714
 vendor SDC
xserver.version: 2:1.17.2-1ubuntu9.1

[penalvch (penalvch)]

David, thank you for reporting this and helping make Ubuntu better.

To see if this is already resolved in Ubuntu, could you please test http://cdimage.ubuntu.com/daily-live/current/ and advise to the results?

[David (david-webber)]

Hi Christopher,

For the daily build xenial-desktop-amd64.iso 12-Jan-2016, touch locations are correct initially but incorrect after changing the resolution.

Upon initial login, the displays and touches are scaled correctly. The initial resolution of the laptop and external display monitors are both 3840x2160. Laptop display is to the left of the monitor.

In unity-control-center, I set the laptop resolution to 1920x1080. Touches did not register in the correct position.

In unity-control-center, I set the laptop resolution back to 340x2160. Touches remained in the wrong position, where touching the right side of the laptop display registered as a touch on the touchless monitor.

Thanks,
David

[David (david-webber)]

*340x2160 -> 3840x2160

[penalvch (penalvch)]

David, to advise, given the originally scoped issue is resolved:
>"With a dual-monitor setup, touchscreen inputs are scaled to the whole desktop region rather than just the touchscreen display."

but a new issue has popped up:
>"locations are correct initially but incorrect after changing the resolution."

It would help immensely if you were to use Xenial going forward, and a new report is created scoped to the new issue via a terminal:
ubuntu-bug xorg

Please feel free to subscribe me to it.

Regarding this report, would you need a backport to a release prior to Xenial, or may this be closed as Status Invalid?

[David (david-webber)]

Hi Christopher,

Agreed, let's close this bug and I'll submit a new one for Xenial.

Thanks,
David