doc/user: update the timer offset warning for the new "too slow" message

Related #533

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

diff --git a/doc/user/faqs.rst b/doc/user/faqs.rst
index 7cd6113..3a9595d 100644 (file)
--- 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:
 
 ------------------------------------------------------------------------------
 .. _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
 ------------------------------------------------------------------------------
 
 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
 
 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
 
 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:
 
 
 .. _faq_wayland: