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<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>
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<a class="bz_bug_link
bz_status_ASSIGNED "
title="ASSIGNED - Debouncing causes "sticky" buttons"
href="https://bugs.freedesktop.org/show_bug.cgi?id=103636">bug 103636</a>
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<th>What</th>
<th>Removed</th>
<th>Added</th>
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<td style="text-align:right;">Status</td>
<td>NEW
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<td>ASSIGNED
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<b><a class="bz_bug_link
bz_status_ASSIGNED "
title="ASSIGNED - Debouncing causes "sticky" buttons"
href="https://bugs.freedesktop.org/show_bug.cgi?id=103636#c2">Comment # 2</a>
on <a class="bz_bug_link
bz_status_ASSIGNED "
title="ASSIGNED - Debouncing causes "sticky" buttons"
href="https://bugs.freedesktop.org/show_bug.cgi?id=103636">bug 103636</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>E: 4.135016 0004 0004 589825 # EV_MSC / MSC_SCAN 589825
E: 4.135016 0001 0110 0000 # EV_KEY / BTN_LEFT 0
E: 4.135016 0000 0000 0000 # ------------ SYN_REPORT (0) ---------- +9ms
E: 4.136733 0004 0004 589825 # EV_MSC / MSC_SCAN 589825
E: 4.136733 0001 0110 0001 # EV_KEY / BTN_LEFT 1
E: 4.136733 0000 0000 0000 # ------------ SYN_REPORT (0) ---------- +1ms
This is your problem. A button left press comes 1ms after the previous button
release, libinput assumes that this is a bouncing button with a flaky contact
and enables button debouncing. From then on, button events are debounced, so
anything within the 12ms debounce timeout will be filtered. See
<a href="https://wayland.freedesktop.org/libinput/doc/latest/button_debouncing.html">https://wayland.freedesktop.org/libinput/doc/latest/button_debouncing.html</a>
When you run libinput debug-events you should see a "Enabling button
debouncing" message when this happens. I question your ability to really
release and click within 1ms though :) I think we need some special timeout to
paper over multiple button releases, afaict this only happens when multiple
buttons change state.
There's another patch on the list atm that will have to be merged first before
we can fix this issue here though
<a href="https://lists.freedesktop.org/archives/wayland-devel/2017-November/035666.html">https://lists.freedesktop.org/archives/wayland-devel/2017-November/035666.html</a></pre>
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