Bug 91230

Summary: Mouse cursor drawn at wrong position while running Unity engine games
Product: xorg Reporter: Daniel Scharrer <daniel>
Component: Driver/RadeonAssignee: xf86-video-ati maintainers <xorg-driver-ati>
Status: RESOLVED FIXED QA Contact: Xorg Project Team <xorg-team>
Severity: normal    
Priority: medium    
Version: git   
Hardware: x86-64 (AMD64)   
OS: Linux (All)   
Whiteboard:
i915 platform: i915 features:
Attachments:
Description Flags
Xorg.0.log
none
dmesg log none

Description Daniel Scharrer 2015-07-05 01:30:07 UTC 
Created attachment 116942 [details]
Xorg.0.log

While running various Unity engine games (tested with  the cursor is drawn slightly offset to the bottom-right of the real position observed by applications. It does not matter whether the cursor is over the game's window or if it has focus or is fullscreen / windowed / iconified.

I have bisected this to the following change in xf86-video-ati:
commit ddaba449e8d6fe9fc0d97085e4045843fd8d7af9
Author: Piotr Redlewski <predlewski@gmail.com>
Date:   Wed Jun 24 18:44:39 2015 +0200

    Disable CRTCs when disabling the outputs
    
    When turning the outputs off (DPMSModeOff), CRTCs stayed enabled. This led
    to higher gpu temperatures than with fglrx driver.
    
    v2: when entering DPMS also disable active CRTCs
    v3: use drmmode_set_mode_major() for enabling CRTCs when leaving DPMS
    
    Signed-off-by: Piotr Redlewski <predlewski@gmail.com>
    Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>

:040000 040000 4cee4e2cdce31663527116812bb616dc0f2d42c6 a4510278e95f9c0006ae2b5d9f2d6caaf589961d M      src


The cursor is drawn at the correct position while not running a Unity engine game.

GPU: Radeon HD 7950 (TAHITI)
Mesa: git-ff0a41b
LLVM: r241381
glamor: git-347ef4f
libdrm: git-676c806
xorg-server: 1.17.1
Comment 1 Daniel Scharrer 2015-07-05 01:30:50 UTC 
Created attachment 116943 [details]
dmesg log
Comment 2 Daniel Scharrer 2015-07-05 01:42:22 UTC 
Additional details: When moving the mouse, the cursor flickers between the correct and offset position. While the mouse is stationary, the cursor is always at the wrong position.

I only have a single monitor connected. In my xorg.conf I have disabled DPMS suspend / etc. (my monitor does not always turn back on without manually turning it off and on again):
Section "ServerLayout"
        Identifier    "layout"
        Screen        0 "screen0" 0 0
        Option        "BlankTime"   "0"
        Option        "StandbyTime" "0"
        Option        "SuspendTime" "0"
        Option        "OffTime"     "0"
EndSection
Comment 4 Daniel Scharrer 2015-07-07 05:45:49 UTC 
Yes, that seems to have fixed it.

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