[Asterisk-Dev] why not disable clock when using multiple Zaptel cards?

[Peter Svensson]

On Fri, 26 Nov 2004, Steven Critchfield wrote:

> Maybe because you may be confusing some terminology. For any T1 or E1
> interface there is timing on the wire and it is not directly tied to the
> IRQs. Timing on the T1/E1 spans are needed to keep them in sync with the
> remote end of the line. The interupt is fired after 8 bits of each
> channel are prepared. The data needs to be picked up before the next 8
> bits are ready. So the timing on the T1/E1 spans needs to be relatively
> perfect. The timing of the interupts has some wiggle room. 

I thought it was after 64 bits (8 samples) = 1 kHz? 
Otherwise I agree.

> As for eliminating the IRQs on any Zap card after the first and letting
> the driver handle each and every zap card there after on the same
> interupt, sounds interesting, but not all zap cards use the same driver.
> T100ps use wct1xxp driver, TDM400P uses wtdm somthing. If they used all
> the same drivers it might be possible, otherwise I think there is a
> kernel issue with servicing the interupt when your device didn't
> generate the interupt.

Those other cards would have to have their interrupts turned off. Does 
anyone have any numbers or even gut feeling if the interrupt overhead is 
significant? 

Peter