# Re: \[PATCH 2.6.21-rt2\] PowerPC: decrementer clockevent driver

- From: Benjamin Herrenschmidt \<benh@kernel.crashing.org\>
- Date: 2007-05-19 00:14:21 
- List: linuxppc-dev
- Page: https://ratatoskr.run/linuxppc-dev/2007/05/957683
- Thread: https://ratatoskr.run/lkml/2007/05/957088/t.md

```text
On Sat, 2007-05-19 at 01:49 +0200, Segher Boessenkool wrote:
> > I find it extremely silly to implement it as edge anyway. The EE line 
> > is
> > level triggered, and having a mix of edge and level on the same
> > exception without a clean way to retrigger the DEC one other than
> > waiting one tick is just causing trouble.
> 
> It isn't edge triggered, it just automatically clears the
> decrementer exception condition at its source when taken

Which is exactly the same thing software-wise as edge triggered... 

Ben.
```