<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEEDINFO " title="NEEDINFO - Lenovo G50-45 ETPS/2 Elantech Touchpad strange behavior." href="https://bugs.freedesktop.org/show_bug.cgi?id=103952#c8">Comment # 8</a> on <a class="bz_bug_link bz_status_NEEDINFO " title="NEEDINFO - Lenovo G50-45 ETPS/2 Elantech Touchpad strange behavior." href="https://bugs.freedesktop.org/show_bug.cgi?id=103952">bug 103952</a> from <a class="email" href="mailto:peter.hutterer@who-t.net" title="Peter Hutterer <peter.hutterer@who-t.net>"> Peter Hutterer</a> <pre>The dimensions only affect pointer acceleration etc, they don't produce the output this recording shows. Grab mtview and run it, then reproduce it. You'll see the jumping touches quickly. <a href="https://github.com/whot/mtview">https://github.com/whot/mtview</a> There is no single definition of ghost touches beyond "the hardware thinks there is a touch where there is none". That's definitely the case here because there's no way this was your physical input. Look at <a href="attachment.cgi?id=135846" name="attach_135846" title="finger pressure map over time">attachment 135846</a> <a href="attachment.cgi?id=135846&action=edit" title="finger pressure map over time">[details]</a>, it illustrates the pressure the recording shows. It's all over the place, and that diagonal line from 20-42s is just odd, no way could you control your finger that precisely that you get a pressure increase like this. If I read <a href="show_bug.cgi?id=103952#c6">comment 6</a> correctly: * no pointer movement when not touching * pointer movement ok when close to the surface without touching * pointer movement crazy when touching I don't know how we could possibly detect this. Your best bet would be to change the pressure ranges and hope that palm detection kicks in for most of the ghost touches. But that's not a guarantee. See <a href="https://wayland.freedesktop.org/libinput/doc/latest/udev_config.html#hwdb">https://wayland.freedesktop.org/libinput/doc/latest/udev_config.html#hwdb</a> for the instructions, this should make your earlier hwdb work.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the assignee for the bug.</li> </ul> </body> </html>