Re: [PATCH 0/2] input: mt: Add helper function to send end events

From: Dmitry Torokhov
Date: Tue Dec 31 2013 - 13:50:45 EST


Hi Henrik,

On Tue, Dec 31, 2013 at 10:26:31AM +0100, Henrik Rydberg wrote:
> Hi Felipe,
>
> > Adds a helper function to send end touch events for active tracking ids.
> > And also implements it in egalax driver.
>
> What problematic scenario is this supposed to solve?
>
> The 'release on suspend' is only an approximation to the 'close
> laptop' scenario, it is certainly not correct in the coffee table
> case,

Why would it not be correct for coffee table? Do we expect the touches
to remain valid while the device is asleep?

> for instance. Instead of
> hardcoding this in the kernel, userland can easily detect long intervals
> directly using the event time.

But with slots it is not only problem with old events being sent out
later, it is that we have mix of old (pre-sleep) and new state.

>
> Unless there is already a reasonable mechanism in your user
> application which deals with cases like this but fails to account for
> your particular problem scenario, the patch will not be applied.
>

We do that for keys (release them when we transition to system sleep)
and I think it might be worthwhile to do the same for touch data.

Thanks.

--
Dmitry
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