Re: [PATCH v3] staging:iio: trigger: Add hrtimer trigger

["Getz, Robin" <robin.getz@analog.com>]

On Mon 16 Apr 2012 12:55, Lars-Peter Clausen pondered:
> On 04/16/2012 06:17 PM, Jonathan Cameron wrote:
> > Lars-Peter Clausen <lars@metafoo.de> wrote:
> >> From: Marten Svanfeldt <marten@intuitiveaerial.com>
> >>
> >> This patch adds a IIO trigger driver which uses a highres timer to
> >> provide a
> >> frequency based trigger.
> >
> > Fine as it stands but same issue arises as we had with userspace trigger
> > still.  What are we doing registering a pure software element not
> > associated to any specific hardware via a platform device.  Why not do it
> > on userspace asking for one as we do with the sysfs file based trigger?
>
> I suppose this is a general question how we want to mange our triggers in
> general. None of the other existing trigger drivers does direct IO access
> and just use existing infrastructure. They could all be easily be
> instantiated by writing a string or number to a sysfs file. So where do we
> draw the line?

Isn't there an issue of accuracy? the timing accuracy of sysfs/userspace is 
non-existant with respect to what you need to do in most of these cases.

-Robin