<html>
    <head>
      <base href="https://bugs.freedesktop.org/">
    </head>
    <body><span class="vcard"><a class="email" href="mailto:peter.hutterer@who-t.net" title="Peter Hutterer <peter.hutterer@who-t.net>"> <span class="fn">Peter Hutterer</span></a>
</span> changed
          <a class="bz_bug_link 
          bz_status_NEW "
   title="NEW - Unreliable tap-to-click on a DELL XPS 9370"
   href="https://bugs.freedesktop.org/show_bug.cgi?id=106044">bug 106044</a>
          <br>
             <table border="1" cellspacing="0" cellpadding="8">
          <tr>
            <th>What</th>
            <th>Removed</th>
            <th>Added</th>
          </tr>

         <tr>
           <td style="text-align:right;">CC</td>
           <td>
                
           </td>
           <td>peter.hutterer@who-t.net
           </td>
         </tr></table>
      <p>
        <div>
            <b><a class="bz_bug_link 
          bz_status_NEW "
   title="NEW - Unreliable tap-to-click on a DELL XPS 9370"
   href="https://bugs.freedesktop.org/show_bug.cgi?id=106044#c1">Comment # 1</a>
              on <a class="bz_bug_link 
          bz_status_NEW "
   title="NEW - Unreliable tap-to-click on a DELL XPS 9370"
   href="https://bugs.freedesktop.org/show_bug.cgi?id=106044">bug 106044</a>
              from <span class="vcard"><a class="email" href="mailto:peter.hutterer@who-t.net" title="Peter Hutterer <peter.hutterer@who-t.net>"> <span class="fn">Peter Hutterer</span></a>
</span></b>
        <pre>The log parts that matter here, for the evemu record from <a href="show_bug.cgi?id=106044#c0">comment 0</a>:

event19 - tap: touch 0 state TAP_STATE_IDLE → TAP_EVENT_TOUCH → TAP_STATE_TOUCH
event19 - tap: touch 1 state TAP_STATE_TOUCH → TAP_EVENT_TOUCH →
TAP_STATE_TOUCH_2
event19 - palm: touch 1: palm-tap detected
event19 - tap: touch 1 state TAP_STATE_TOUCH_2 → TAP_EVENT_MOTION →
TAP_STATE_TOUCH_2_HOLD
event19 - tap: touch 1 state TAP_STATE_TOUCH_2_HOLD → TAP_EVENT_RELEASE →
TAP_STATE_HOLD
event19 - tap: touch 0 state TAP_STATE_HOLD → TAP_EVENT_RELEASE →
TAP_STATE_IDLE

So basically what this means:
- touch down
- second touch down
- second touch is detected as palm touch because it's at the far edge of the
touchpad
- this puts the first touch into the "touch-and-hold" state

IOW, if a palm is detected during tapping, we don't continue with the tap
because there's too much chance of interference. That's the reason that you
don't get a one-finger tap with two fingers (one of which is a palm). And the
reason you don't get a two-finger tap is because one touchpoint is in the palm
detection area on the far side of the touchpad. This is an intentional
behaviour, see:
<a href="http://wayland.freedesktop.org/libinput/doc/latest/palm_detection.html">http://wayland.freedesktop.org/libinput/doc/latest/palm_detection.html</a></pre>
        </div>
      </p>


      <hr>
      <span>You are receiving this mail because:</span>

      <ul>
          <li>You are the assignee for the bug.</li>
      </ul>
    </body>
</html>