Spurious double-clicks in 2.6.0

Spurious double-clicks in 2.6.0

[Rob Landley]

I recently had the opportunity to compare 2.6 and 2.4 on my thinkpad, and 
although most things are greatly improved in 2.6, one thing stands out.

When I click on things in 2.6, about 1% of the time it double-clicks instead.  
(Clicking on a titlebar to raise the window causes it to roll up instead, 
clicking on a scrollbar causes it to page down twice instead of once, etc.  
I'm always afraid that pulling up the top left window menu (to move it to 
another desktop, make it always on top, etc) will kill the window instead...)

This just doesn't happen under 2.4: I used the default kernel of Fedora Core 1 
for several days after a recent reinstall before putting 2.6 back on the box.  
But the input core doesn't seem to have this detail yet.

In 2.4 there seems to be some minimum time required between clicks to count as 
a double-click, which nicely filters out this kind of suprious electrical 
contact bounce thing.  (This makes sense: a human being simply CAN'T click 
twice within 1/20th of a second.  The mouse driver should drop a second click 
that comes faster than that: it's keybounce from the previous click.)

Rob

Re: Spurious double-clicks in 2.6.0

[Vojtech Pavlik]

On Mon, Dec 29, 2003 at 11:54:14PM -0600, Rob Landley wrote:
> I recently had the opportunity to compare 2.6 and 2.4 on my thinkpad, and 
> although most things are greatly improved in 2.6, one thing stands out.
> 
> When I click on things in 2.6, about 1% of the time it double-clicks instead.  
> (Clicking on a titlebar to raise the window causes it to roll up instead, 
> clicking on a scrollbar causes it to page down twice instead of once, etc.  
> I'm always afraid that pulling up the top left window menu (to move it to 
> another desktop, make it always on top, etc) will kill the window instead...)
> 
> This just doesn't happen under 2.4: I used the default kernel of Fedora Core 1 
> for several days after a recent reinstall before putting 2.6 back on the box.  
> But the input core doesn't seem to have this detail yet.
> 
> In 2.4 there seems to be some minimum time required between clicks to count as 
> a double-click, which nicely filters out this kind of suprious electrical 
> contact bounce thing.  (This makes sense: a human being simply CAN'T click 
> twice within 1/20th of a second.  The mouse driver should drop a second click 
> that comes faster than that: it's keybounce from the previous click.)

Reconfigure X only to use one mouse source (either /dev/psaux or
/dev/input/mice, not both). Since in 2.6 the mouse inputs are already
mixed in the kernel for these two devices, X then gets all the data
twice, resulting in random doubleclicks.

-- 
Vojtech Pavlik
SuSE Labs, SuSE CR