Benjamin Deering <[email protected]> writes:

> I seem to remember that part of the touchscreen filtering is disabled
> on gta04.  Does anyone remember why and do we know if it still needs
> to be disabled?

Yes, this has indeed been discussed before, but I believe with no action
or resolution yet.  The following is what I could turn up; I think the
important idea is just the last paragraph, i.e. to look at tslib.

> From: NeilBrown <[email protected]>
> Subject: Re: [Gta04-owner] Beta Tester's Report on qtmoko v40
> To: List for communicating with real GTA04 owners <[email protected]>
> Cc: [email protected]
> Date: Tue, 28 Feb 2012 10:34:32 +1100
> 
> On Mon, 27 Feb 2012 23:06:47 +0000 Neil Jerram <[email protected]>
> wrote:
> 
> > Sven Dyroff <[email protected]> writes:
> > 
> > > Handling the touch
> > > I don't think that I'll get familiar with that behaviour. For me it's just
> > > nasty. Please give me at least a hint where I can play with what values 
> > > and
> > > I'll try to squeeze out a more comfortable touch reaction.
> > 
> > I think you said before that it was too jittery - is that correct?  I
> > think I'm sometimes seeing the same problem.
> > 
> > I don't know what the solution is, or even how to investigate further,
> > but:
> > 
> > - I think I remember a mailing list thread about dejittering support
> >   having been removed from the kernel recently (approx in the last year
> >   or so), and hence needing to be added to tslib instead.  Or perhaps
> >   vice versa?
> > 
> > - When googling for this, I came across tsc2007_platform_data, and its
> >   max_rt, poll_delay and poll_period fields that were recently added by
> >   Thierry Reding.  I wonder if these fields might help us?
> > 
> >   For GTA04 the tsc2007_platform_data struct initialisation (in
> >   arch/arm/mach-omap2/board-omap3gta04.c) doesn't set these fields, so I
> >   presume they're all implicitly 0.
> 
> Correct - which means the defaults are used.
> 
> max_rt is an upper-bound for the pressure.  If it senses a higher pressue it
> will ignore it.  I wonder why you would do that?  Maybe a high pressue number
> is considerred to be an error?
> It defaults to MAX_12BIT which means no pressures are ignored.
> 
> poll_delay is never used.
> 
> poll_period is a number of msec (defaults to '1' but is rounded up to
> jiffies, so probably about 5).  It represents how often the current stylus
> location is polled.  I doubt increasing that would help much.
> 
> > 
> > I wondered about experimenting with those fields, but it would be a
> > major pain to have to rebuild and reinstall the kernel for every set of
> > values to try.
> > 
> > Any other thoughts on dejittering?
> 
> tslib has dejitter code.  See "man 5 tslib.conf".  That is where I would look
> to try to improve touchscreen response.
> 
> NeilBrown
_______________________________________________
Shr-devel mailing list
[email protected]
http://lists.shr-project.org/mailman/listinfo/shr-devel

Reply via email to