So I am using an Elitebook 8540p running Fedora 25 and have been trying to enable middle mouse scrolling so that I can use the pointing stick for scrolling. The device is listed as PS/2 Generic Mouse by xinput and I have tried messing with the properties of that device but nothing I do will allow me to scroll. Here are the current settings:Device 'PS/2 Generic Mouse':Device Enabled (139):   1Coordinate Transformation Matrix (141): 1.000000, 0.000000, 0.000000, 0.000000, 1.000000, 0.000000, 0.000000, 0.000000, 1.000000Device Accel Profile (265): 0Device Accel Constant Deceleration (266):   1.000000Device Accel Adaptive Deceleration (267):   1.000000Device Accel Velocity Scaling (268):    10.000000Device Product ID (263):    2, 1Device Node (262):  /dev/input/event4Evdev Axis Inversion (269): 0, 0Evdev Axes Swap (271):  0Axis Labels (272):  Rel X (149), Rel Y (150)Button Labels (273):    Button Left (142), Button Middle (143), Button Right (144), Button Wheel Up (145), Button Wheel Down (146), Button Horiz Wheel Left (147), Button Horiz Wheel Right (148)Evdev Scrolling Distance (274): 0, 0, 0Evdev Middle Button Emulation (275):    0Evdev Middle Button Timeout (276):  50Evdev Middle Button Button (277):   2Evdev Third Button Emulation (278): 0Evdev Third Button Emulation Timeout (279): 1000Evdev Third Button Emulation Button (280):  3Evdev Third Button Emulation Threshold (281):   20Evdev Wheel Emulation (282):    1Evdev Wheel Emulation Axes (283):   6, 7, 4, 5Evdev Wheel Emulation Inertia (284):    10Evdev Wheel Emulation Timeout (285):    200Evdev Wheel Emulation Button (286): 2Evdev Drag Lock Buttons (287):  0
Enable middle button scrolling with HP pointing stick
fedora;x11;gnome;hardware compatibility
It appears that this feature is simply not supported for this device on this version of Fedora. I was able to get this feature working on an old IBM USB keyboard that had a trackpoint so I will just be using that instead of the keyboard built into the laptop.