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frumble

Member

From: Germany

Registered: 2012-05-20

Posts: 164

Website

Magic Trackpad with Synaptics: Input lag on first touch after 3 s [✔]

Hey, I just reinstalled my system and now I get a strange behavior with my Magic Trackpad on Plasma 5.4. It works as it should but each first touch gets delayed. Directly following touches are recognized normal. But after a pause of three seconds with non-touching, the pointer lags again for ~half a second. I've been using this Magic Trackpad since 2011 with many distros and I've never got this effect before. I have recorded a video for you (you don't need to watch it the whole way through): https://youtu.be/hDtlz9D4XQI

My current synaptics settings are:

$ synclient -l                
Parameter settings:
    LeftEdge                = -2393
    RightEdge               = 2651
    TopEdge                 = -2030
    BottomEdge              = 2139
    FingerLow               = 70
    FingerHigh              = 75
    MaxTapTime              = 180
    MaxTapMove              = 346
    MaxDoubleTapTime        = 100
    SingleTapTimeout        = 180
    ClickTime               = 100
    EmulateMidButtonTime    = 0
    EmulateTwoFingerMinZ    = 282
    EmulateTwoFingerMinW    = 7
    VertScrollDelta         = 157
    HorizScrollDelta        = 157
    VertEdgeScroll          = 0
    HorizEdgeScroll         = 0
    CornerCoasting          = 0
    VertTwoFingerScroll     = 1
    HorizTwoFingerScroll    = 0
    MinSpeed                = 1
    MaxSpeed                = 1.75
    AccelFactor             = 0.0253743
    TouchpadOff             = 0
    LockedDrags             = 0
    LockedDragTimeout       = 5000
    RTCornerButton          = 0
    RBCornerButton          = 0
    LTCornerButton          = 0
    LBCornerButton          = 0
    TapButton1              = 1
    TapButton2              = 2
    TapButton3              = 3
    ClickFinger1            = 1
    ClickFinger2            = 3
    ClickFinger3            = 2
    CircularScrolling       = 0
    CircScrollDelta         = 0.1                                                                                                          
    CircScrollTrigger       = 0                                                                                                            
    CircularPad             = 0                                                                                                            
    PalmDetect              = 0                                                                                                            
    PalmMinWidth            = 10                                                                                                           
    PalmMinZ                = 200                                                                                                          
    CoastingSpeed           = 20                                                                                                           
    CoastingFriction        = 50                                                                                                           
    PressureMotionMinZ      = 30                                                                                                           
    PressureMotionMaxZ      = 160                                                                                                          
    PressureMotionMinFactor = 1                                                                                                            
    PressureMotionMaxFactor = 1                                                                                                            
    GrabEventDevice         = 0                                                                                                            
    TapAndDragGesture       = 1                                                                                                            
    AreaLeftEdge            = 0                                                                                                            
    AreaRightEdge           = 0                                                                                                            
    AreaTopEdge             = 0                                                                                                            
    AreaBottomEdge          = 0                                                                                                            
    HorizHysteresis         = 4                                                                                                            
    VertHysteresis          = 4                                                                                                            
    ClickPad                = 1                                                                                                            
    RightButtonAreaLeft     = 129                                                                                                          
    RightButtonAreaRight    = 0                                                                                                            
    RightButtonAreaTop      = 1661
    RightButtonAreaBottom   = 0
    MiddleButtonAreaLeft    = 0
    MiddleButtonAreaRight   = 0
    MiddleButtonAreaTop     = 0
    MiddleButtonAreaBottom  = 0

Can anyone help?

Last edited by frumble (2015-10-31 19:51:12)

frumble

Member

From: Germany

Registered: 2012-05-20

Posts: 164

Website

Re: Magic Trackpad with Synaptics: Input lag on first touch after 3 s [✔]

Solved! It had to do with my USB port. I have some problems with my IOMMU and iommu=soft boot parameter on my Gigabyte 990FXA-UD3. Don't know why, but I had to switch the Bluetooth adapter to an USB port on a separate PCI card. Now, the strange input lag on first touch is gone.