<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_REOPENED " title="REOPENED - RFE: keyboard debouncing" href="https://bugs.freedesktop.org/show_bug.cgi?id=105222#c7">Comment # 7</a> on <a class="bz_bug_link bz_status_REOPENED " title="REOPENED - RFE: keyboard debouncing" href="https://bugs.freedesktop.org/show_bug.cgi?id=105222">bug 105222</a> from <a class="email" href="mailto:peter.hutterer@who-t.net" title="Peter Hutterer <peter.hutterer@who-t.net>"> Peter Hutterer</a> <pre>Created <a href="attachment.cgi?id=137597" name="attach_137597" title="keyboard state">attachment 137597</a> <a href="attachment.cgi?id=137597&action=edit" title="keyboard state">[details]</a> keyboard state I wrote a tool to visualise what your keyboard does, see here: <a href="https://github.com/whot/input-data-analysis/blob/master/keyboard-state/keyboard-state.py">https://github.com/whot/input-data-analysis/blob/master/keyboard-state/keyboard-state.py</a> The generated output for your event recording is attached and it shows a number of issues. First, there doesn't seem to be a consistent prediction of when the keyboard bounces. Look at the * rows in the output, these mark events with less than 3ms. Initially I ran this on 8ms and that's even more. I was hoping we'd only get these when multiple keys are down but that doesn't seem to be the case. This makes debouncing a lot harder, because we'll inevitable end up having to discard key events. The one you mentioned at 10.735 can only be debounced if the initial space key press is discarded, the second press does not come in until 32ms later. For reference, the button debounce timeouts are 12 and 25ms, and some consider that too long. Googling around for the issue indicates this is a common enough (hardware) problem: <a href="https://www.dell.com/community/General/Precision-5510-keyboard-douuble-characters/m-p/4758956">https://www.dell.com/community/General/Precision-5510-keyboard-douuble-characters/m-p/4758956</a> <a href="https://www.reddit.com/r/Dell/comments/5qydpb/keyboard_repeat_issues_wdell_xps_15_9560/">https://www.reddit.com/r/Dell/comments/5qydpb/keyboard_repeat_issues_wdell_xps_15_9560/</a> and it appears the hw may be the same as the XPS for which you can find even more complaints. I really suggests taking this up with Dell to get a fix. Honestly, this is something I'm very reluctant to fix in libinput. It'll cost a lot of time and effort, is likely to break thinks for other users and appears to be a hardware bug.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the assignee for the bug.</li> </ul> </body> </html>