Very strange problem with input events

[Cedric Sodhi]

On Thu, Jun 14, 2012 at 07:19:22PM +1000, Peter Hutterer wrote:
> On 14/06/12 17:35 , Cedric Sodhi wrote:
> > On Thu, Jun 14, 2012 at 01:52:28PM +1000, Peter Hutterer wrote:
> >> On Wed, Jun 13, 2012 at 09:02:52PM +0200, Cedric Sodhi wrote:
> >>> Unfortunally, I lack a better or just more precise description of my
> >>> problem. I get strange behaviour all throughout X, everywhere clicks are
> >>> involved.
> >>>
> >>> One thing I think I had already mentioned is that my touchscreen, which
> >>> runs evdev does work properly everywhere, but there are no regular
> >>> events generated - only XI events.
> >>
> >> this can only be a client issue. I can't tell you which client from here
> >> though. The drivers and the server don't deal with core vs XI events until
> >> very late. There' internal events and then based on the client selection
> >> that internal event structure is converted to the wire event and sent.
> >>
> >> So if you don't see core events, the clients haven't registered for it, or
> >> clients have otherwise registered for XI events and take precedence over
> >> core..
> >>
> >>> Also, many applications strangely misbehave in a way that other people
> >>> cannot possibly reproduce. Unrelated to the touchscreen, that is. Using
> >>> an ordinary mouse with evdev.
> >>>
> >>> Two examples:
> >>>
> >>> Tint2 (the panel) had me "drag" window-icons ("tasks") on the taskbar,
> >>> when I clicked them, as if I had held the mouse button down. I was able
> >>> to "fix" that by a minor change in the code of tint2, but as no one else
> >>> is getting any such behaviour I assume I did not really fix the bug but
> >>> only found some solution to somewhich, which fails elsewhere. I was not
> >>> able to track the logic which is supposed to run, though.
> >>>
> >>> Second example, Midori (the browser). When I right click a hyperlink and
> >>> subsequently left click an entry in the context menu, the context menu
> >>> disappears (as it should) and I'm suddenly "dragging" the link upon
> >>> which I clicked.
> >>>
> >>> Similar things happen everywhere else, too.
> >>>
> >>> I'm not even sure where to start looking. I wish I could get a
> >>> suggestion from you, what to do.
> >>
> >> options are trying an older X servers and bisecting from a good one if you
> >> can find one.
> >>
> >> or look at the protocol with xscope to see the actual events sent on the
> >> wire (you can also use systemtap/dtrace for that but it's less pretty).
> >>
> >> For the link issue, I'd check the evtest output of the touchscreen to see if
> >> the actual device data makes sense.
> >
> > I take back what I said previously, that it was unrelated to the
> > touchscreen. In fact, I narrowed down the source of the problem exactly
> > to the touchscreen. It appears that if I do not touch the touchscreen at
> > all, after the server has started, everything works.
> >
> > But as soon as I touched it at least once - thought there appears to be
> > no sign of problems at first - these strange things (see the two
> > examples above - I've got more examples, if you like) start happening,
> > even if I just use the normal mouse. I had attached an evtest log of the
> > device, do you see any indication of problems in that?
> 
> disable the device in X with xinput and run mtview against it, that 
> should tell you if the device misbehaves. the log looks ok on a glance.
> 
> https://github.com/whot/mtview/


Ok, I think I noticed a few irregularities. Here is what I did: