On Thu, 2006-10-12 at 13:05 -0700, Open Source wrote:
> Hi,
> 
> Thanks for the rapid response!  But...I'm a bit confused.  Why is there any 
> software OS timer involved at all?  Bulk messages should be scheduled by the 
> host controller and for USB 2.0 the microframe period is 125 us.  When I 
> submit an URB, it should be sent to the host controller and scheduled for the 
> next microframe.  When the URB completes I should get an interrupt from the 
> hardware.  Hence, my transactions (WRITE followed by READ) should at worst be 
> approximately 250 us plus some overhead to process the transaction itself, 
> provided there aren't any other time consuming processes running on my OS.  
> My overhead is less than 250 us.  I was willing to tolerate 1 ms per 
> transaction, but 4 ms just doesn't make any sense.  Therefore I'm not sure if 
> CONFIG_HZ is an appropriate excuse for this issue.
> 

I don't know, it just seemed likely because 1ms vs 4ms is close to the
change in the timer tick rate.  Try it.

Lee


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