> -----Original Message----- From: Gilles Chanteperdrix
> 
> The reason for not looping is that Adeos never looses interrupts. If
> we leave the loop and Linux gets delayed, then the lost ticks will
> be accounted for twice: one time because Xenomai will have posted
> the missed timer interrupts, one time because of the loop. So, we
> remove the loop.

Got it.

I'll post a new patch today with your corrections.

> It's explained in the wiki. The PXA timer does not tick if
> programmed with too short delays. To see if IXP4XX has the same
> problem, remove the "if" and run latency with a tight period, so
> that the timer is reprogrammed with short delays. If latency
> misteriously hangs, then you have the same problem as PXA, and you
> should look for the minimum delay by trial and errors.

AFAICT, the only hardware minimum would be 4 ticks (60 nanoseconds at
66.66 MHz), because you cannot set the two low order bits in the
reload register. However, since the ISR requires at least a few
microseconds, perhaps we should set some sanity value, like 5 usec.

Thanks,
Richard

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