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| -rw-r--r-- | doc/user/faqs.rst | 28 |
1 files changed, 14 insertions, 14 deletions
diff --git a/doc/user/faqs.rst b/doc/user/faqs.rst index 7cd6113d..3a9595da 100644 --- a/doc/user/faqs.rst +++ b/doc/user/faqs.rst @@ -287,28 +287,28 @@ details on the hwdb and how to modify it locally. .. _faq_timer_offset: ------------------------------------------------------------------------------ -What causes the "timer offset negative" warning? +What causes the "your system is too slow" warning? ------------------------------------------------------------------------------ libinput relies on the caller to call **libinput_dispatch()** whenever data is -available on the epoll-fd. Doing so will process the state of all devices -and can trigger some timers to be set (e.g. palm detection, tap-to-click, -disable-while-typing, etc.). Internally, libinput's time offsets are always -based on the event time of the triggering event. +available. **libinput_dispatch()** will process the state of all devices, +including some time-sensitive features (e.g. palm detection, tap-to-click, +disable-while-typing, etc.). -For example, a touch event with time T may trigger a timer for the time T + -180ms. When setting a timer, libinput checks the wall clock time to ensure -that this time T + offset is still in the future. If not, the warning is -logged. +If the time between the event and the call to **libinput_dispatch()** +is excessive, those features may not work correctly. For example, a delay in +touch event processing may cause wrong or missing tap-to-click events or +a palm may not be detected correctly. When this warning appears, it simply means that too much time has passed -between the event occurring (and the epoll-fd triggering) and the current -time. In almost all cases this is an indication of the caller being -overloaded and not handling events as speedily as required. +between the event occurring and the current time. In almost all cases this +is an indication of the caller being overloaded and not handling events as +speedily as required. The warning has no immediate effect on libinput's behavior but some of the -functionality that relies on the timer may be impeded (e.g. palms are not -detected as they should be). +functionality that relies on the timer may be impeded. This is not a bug in +libinput. libinput does not control how quickly **libinput_dispatch()** is +called. .. _faq_wayland: |