[PATCH] ClickPad support v4

Yan Li yan.i.li at intel.com
Tue Dec 28 18:43:03 PST 2010

On Sun, 2010-12-19 at 01:38 +0800, Chris Bagwell wrote:
> On Sat, Dec 18, 2010 at 7:17 AM, Yan Li <yan.i.li at intel.com> wrote:>
> > So I suggest we rework this ClickPad patch, keep only the clicking
> > interpretation part and remove the area limit, and try to fix the jumpy
> > cursor problem (and I'm using JumpyCursorThreshold patch v5 I linked
> > above in MeeGo, so far the feedback is very good).
> >
> Thank for detailed reply.  Do you mind helping me understand how
> touchpad is being used when jumps occur?  Is use case:
> * Move cursor to area you want to click with 1 finger.  Pick up 1
> finger.  Click in button area with 1 finger.
> or
> * Move cursor to area you want to cick with 1 finger.  Leave 1 finger
> on pad.  Click in button area with 2nd finger.

It's the second one. When I use the netbook in fast action I can't
guarantee that I have 1st finger left the touchpad before I tap the
button area.

> First case would move cursor a little bit because of how sensitive
> touchpads are and lots of X/Y can be sent between time of touch and
> button press completed.  But it should not be large jump.  We may need
> to add a gesture style delay when touching in button area so we can
> tell difference between button press and real movement.

First case is not a problem for me.

> Second case seems more likely to cause a jump but a) synpatics
> hardware continues to report 1st finger's X/Y during double touch and
> b) we have code to expect a jump just in case during that second touch
> based on either doubletap or finger width.  Are you working with
> non-synaptics clickpads?

However, this ClickPad doesn't support multi-finger nor finger width.
I'm 90% sure the touchpad used in Lenovo IdeaPad S10-3t is a Synaptics
ClickPad (at least the kernel dmesg says so).

Because it can't detect two-finger nor send finger width, the current
jump-prevention setting is not triggered. That's why I'm using the fix
of JumpyCursorThreshold patch v5 in MeeGo.

> Is there any chance you could reproduce basic sequence when jumps
> occur but using evtest and send me the output?

I'll have a try later. Oh I have to build a driver without
JumpyCursorThreshold patch for this testing.

> This is one of those problems really buggy me for some reason and I'd
> like to help resolve it.

Thanks. Me too.

Best regards,
Li, Yan

MeeGo Team, Opensource Technology Center, SSG, Intel
Office tel.: +86-10-5751-1695 (inet: 8-751-1695)
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