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Date: Mon, 18 Jan 2010 23:28:54 +0800
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Subject: got problem with timer interrupt
From: "wilbur.chan" <wilbur512@gmail.com>
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A timer has been added into my system, and it  is used to generate
continuous interrupt every 1 ms.

This hw is register by request_irq(19, handler_1ms)

Howeve I found that , it is longer than 1 ms between two interrupts,
for I used get_cycles everytime we entered

do_irq :

  if(irq==19)
     {
        delta = get_cycle()-old;
     }

  but to find that delta is always larger than cpu cycles between 1ms.


Does anyone know why this happened?


regards,