Mouse issue

Peter Hutterer peter.hutterer at
Mon Mar 15 18:22:14 PDT 2010

On Mon, Mar 15, 2010 at 05:02:46PM -0800, John Ettedgui wrote:
> On Mon, Mar 15, 2010 at 4:46 PM, Peter Hutterer
> <peter.hutterer at> wrote:
> > On Mon, Mar 15, 2010 at 10:57:48AM -0800, John Ettedgui wrote:
> >> Hello everyone,
> >>
> >> I have had a small issue for some time with my mouse and need some help :)
> >>
> >> Basically sometimes, something bad happens (what?) and then the mouse
> >> keeps the focus on one application.
> >> For example if I am in Firefox and the mouse works there, I cannot
> >> click on anything in the task bar, or even if I alt-tab to konsole the
> >> mouse will not work there. If I right click in the console, it will
> >> behave the same way as if I was right clicking in Firefox.
> >> One "temp fix" is to right click in the application, then right click
> >> in the systray on the same application then I can click on another
> >> application and so on...
> >> This issue is usually fixed by reinstall Xorg's evdev and then restarting Xorg.
> >
> > this is almost certainly a stuck grab. If FF has an active grab, no other
> > application can receive pointer events for the duration of the grab.
> > You don't actually need to reinstall, usually restarting X is enough. In
> > fact, making the FF window unviewable will break the grab too (e.g.
> > minimising it)
> >
> > This may be an application issue or an issue with the server. To figure out
> > what exactly happens, we'd need a reproducible test case - stuck grabs are
> > notoriously tricky to debug.
> >
> > Cheers,
> >  Peter
> >
> Hello Peter,
> in the past I believe just restarting Xorg was not enough, but I'll
> try that again next time and see.
> What do you mean by reproducible? Since this *seems* random it is
> quite hard for me to offer any repro.

Usually, with stuck grabs we need to have a look at the protocol stream when
the grab activates and the events afterwards. That can then be compared
against the same stream from an older X server release that didn't exhibit
this problem to figure out what changed. Since the protocol stream results
in thousands of lines of output even for a short duration of the app, having
it run for ages often isn't an option. Also, monitoring the protocol slows
the application down, sometimes resulting in the bug not appearing when you
monitor the app.

So we need you to help us find a way how to reproduce the issue reliably.
Since it is a grab, it's likely caused by a popup or dropdown menu or
even scrolling. If you take more attention to your actions in the next few
days, you might be able to recognise a pattern that triggers the bug. Then
you can start poking at FF to intentionally reproduce it.


More information about the xorg mailing list