[Bug 1001456] HAL misses Interrupt Clear-Pending Registers handling: wasted processing power

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Bernd Edlinger <bernd.edlinger@hotmail.de> changed:

           What    |Removed                     |Added
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                 CC|                            |bernd.edlinger@hotmail.de

--- Comment #28 from Bernd Edlinger <bernd.edlinger@hotmail.de> 2012-09-27 13:38:45 BST ---
Hi Bernard,

just one thing...

personally I would not like to add more Kernel APIs unless it is absolutely
necessary.

In the hal/arm subtree when there is an interrupt, the function
hal_IRQ_handler() gets called first. This function determines the
highest priority irq, and updates the ISR (in service register),
this would be a place to clear the interrupt pending bit for your architecture.

Suppose the clear pending is done automatically in hal_IRQ_handler()
and hal_interrupt_acknowledge is empty, then this would be a safe way
to write the isr/dsr in the driver:

isr()
{
  HAL_INTERRUPT_MASK(vector);
  HAL_INTERRUPT_ACKNOWLEGE();
  return CALL_DSR;
}


dsr()
{
   now handle interrupt...

   HAL_INTERRUPT_UNMASK(vector);
}

this is in fact how most drivers are already written today.

would'nt that be OK for you too?

Regards,
Bernd Edlinger

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