Re: [RESEND][PATCH] input: Added TSC2003

From: Thierry Reding
Date: Tue Jun 16 2009 - 02:20:54 EST


* Richard RÃjfors wrote:
> On 09-06-15 20.10, Trilok Soni wrote:
> > Hi,
> >
> > On Mon, Jun 15, 2009 at 8:39 PM, Richard
> > RÃjfors<richard.rojfors.ext@xxxxxxxxxxxxxxx> wrote:
> >> Supplied is a driver for the TSC2003. There is actually a driver for TSC2007 which can be used in some cases.
> >> The platform struct is reused from the TSC2007.
> >> There is a big difference in the implementation between the drivers, this one does not use HR timers.
> >> The TSC2007 driver performs synchronous I2C in the timer callback (SW IRQ context) which is bad when
> >> the I2C driver is interrupt driven.
> >>
> >
> > Meaning? I think I2C transaction can sleep.
>
> Yes that's what it means, and that's bad in a HR timer callback.

Note that my patch to the tsc2007 to support the tsc2003 exactly fixes this
problem. It moves the actual I2C transfers into a workqueue, so no sleeping
functions are called from the hrtimer callback.

Thierry
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