Bug 159565

Summary:	Display settings for xinerama show one big screen
Product:	[Unmaintained] kcontrol	Reporter:	Mike <mike>
Component:	kcmdisplay	Assignee:	Daniel Molkentin <molkentin>
Status:	RESOLVED UNMAINTAINED
Severity:	normal	CC:	finex
Priority:	NOR
Version:	unspecified
Target Milestone:	---
Platform:	Compiled Sources
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description Mike 2008-03-19 13:53:38 UTC

Version:            (using Devel)
Installed from:    Compiled sources
OS:                Linux

In systemsettings -> Display multiple screens are shown as one.

I realize that technically it is one display because thats how TwinView works, but everything else (nvidia-settings, plasma, kwin) treats them as 2 separate displays.

The major problem is that you cannot set the refresh rate for each screen independently.

My setup is

screen 0 = 1280X1024 (on right) - 60Hz
screen 1 = 1680X1050 (on left) - 60Hz

systemsettings makes the refresh rate 50Hz and I get really bad tearing (Fullscreen video is impossible).  VSync is enabled in nvidia-settings but KDE keeps setting it back to 50Hz.

The only options in systemsettings are Auto, 50 and 51Hz.  Setting it to Auto does not work, it just reverts back to 50Hz.

Here is the output from from systemsettings when selecting the display tab.

systemsettings(2231) MainWindow::selectionChanged: Selected item:  "Display"
systemsettings(2231) MainWindow::selectionChanged: Comment:        "Display Settings"
systemsettings(2231) MainWindow::selectionChanged: adding
systemsettings(2231)/kutils (KCModuleProxy) KCModuleProxyPrivate::loadModule: Module not already loaded, loading module  "Size & Orientation"  from library  "kcm_randr"  using symbol  "kcm_randr"
systemsettings(2231) RandRDisplay::RandRDisplay: Using XRANDR extension 1.2 or greater.
systemsettings(2231) RandRDisplay::RandRDisplay: XRANDR error base:  185
systemsettings(2231) RandROutput::setCrtc: Setting CRTC 427 on output "default"
systemsettings(2231) RandROutput::queryOutputInfo: Output name: "default"
systemsettings(2231) RandROutput::queryOutputInfo: Output refresh rate: 50
systemsettings(2231) RandROutput::queryOutputInfo: Output rect: QRect(0,0 2960x1050)
systemsettings(2231) RandROutput::queryOutputInfo: Output rotation: 1
systemsettings(2231): ""UnifiedRect" - conversion of "0,0,0,0" to QRect failed"
systemsettings(2231) RandRCrtc::applyProposed: [CRTC] Going to apply ( 427 ) ....
systemsettings(2231) RandRCrtc::applyProposed:        Current Screen rect:  QRect(0,0 2960x1050)
systemsettings(2231) RandRCrtc::applyProposed:        Current CRTC Rect:  QRect(0,0 2960x1050)
systemsettings(2231) RandRCrtc::applyProposed:        Current Rotation:  1
systemsettings(2231) RandRCrtc::applyProposed:        Proposed rect:  QRect(0,0 2960x1050)
systemsettings(2231) RandRCrtc::applyProposed:        Proposed rotation:  1
systemsettings(2231) RandRCrtc::applyProposed:        Proposed refresh rate:  50
systemsettings(2231) RandRCrtc::applyProposed:        Outputs:
systemsettings(2231) RandRCrtc::applyProposed:                -  "default"
systemsettings(2231) KRandRModule::load: Loading KRandRMode...
systemsettings(2231) OutputConfig::load: Loading output configuration for  "default"
systemsettings(2231) OutputConfig::load:   Setting graphic rect pos:  QPoint(0,0)
systemsettings(2231) RandRConfig::load: Output rect:  QRect(0,0 2960x1050)
systemsettings(2231) MainWindow::selectionChanged: adding
systemsettings(2231)/kutils (KCModuleProxy) KCModuleProxyPrivate::loadModule: Module not already loaded, loading module  "Power Control"  from library  "kcm_energy"  using symbol  "kcm_energy"
systemsettings(2231)/kutils (KCModuleProxy) KCModuleProxy::showEvent:

Comment 1 Elad Lahav 2008-04-09 15:37:47 UTC

I don't think that 50MHz are a KDE bug. This is Nvidia's way of distinguishing between screens. Screen 0 always reports 50 MHz and screen 1 reports 51 MHz, even though those are not the true refresh rates.
You can verify this by using the monitor's OSD - there is usually an "information" screen that shows you the current refresh rate.

Comment 2 Mike 2008-04-09 15:53:42 UTC

You are right, the OSD's for the screens both show a refresh rate is 60Hz.

I still get a lot of horizontal tearing (especially in fullscreen).  Is this a driver problem too?

Comment 3 Hal V. Engel 2009-03-01 00:30:13 UTC

Also your title "Display settings for xinerama show one big screen"  is completely wrong since your issue was with TwinView not xinerama.   These are two completely different animals.

Comment 4 Andrew Crouthamel 2018-09-04 18:05:00 UTC

Hello! Sorry to be the bearer of bad news, but this project has been unmaintained for many years so I am closing this bug. Kcontrol has been replaced by System Settings in Plasma. Please give the latest version of that a try, and open a new bug in "systemsettings" if you continue to have an issue. Thank you!