Hi Eric --
--- In ts-7000%40yahoogroups.com, "Eric Robishaw" <> wrote:
>
> It doesn't appear to be a sleep issue... as I believe usleep calls
nanosleep
It shows up as a sleep issue, ...
> anyhow.
> I just can't read the registers any faster than 50hz (see Jim's
message if
> you haven't already).
And I have ... The issue is timer resolution. As Jim correctly said,
the timer resolution is 10 mS in normal cases. You asked for a sleep
period of at least 10 mS, so the delay ends up being 10 mS, plus
another 10 mS for the process to become runnable again. Your total
delay is 20 mS, and 1/.02 = 50 Hz.
The high resolution timers in recent kernels is clean way to solve
this problem, *transparently* giving timers resolution of 1 nS,
without having to write a special kernel driver to use an available HW
counter. It works great on the other TS boards (ep93xx based), but I
don't know if a) it was available when the TS ts=7800 kernel was
branched, or b) if TS enabled it; hence my suggestion.
Jim is also right that it is a FAQ, and you can find lots more
discussion about it in the archives and the site I gave you.
But in any case, good luck with your project!
Regards, ........ Charlie
>
> Eric
>
>
>