[ECOS] Re: hal_IRQ_handler() for AT91 port

[Gary Thomas <gthomas at redhat dot com>]

On Wed, 2001-10-17 at 19:39, Ilko Iliev wrote:
> Hi Gary!
> 
> Why did you make :
> 
> in at91_misc.c
> int hal_IRQ_handler(void)
> {
>      cyg_uint32 irq_num;
>      cyg_uint32 ipr, imr;
> 
>      HAL_READ_UINT32(AT91_AIC+AT91_AIC_IPR, ipr);
>      HAL_READ_UINT32(AT91_AIC+AT91_AIC_IMR, imr);
>      ipr &= imr;
>      for (irq_num = 0;  irq_num < 19;  irq_num++) {
>          if (ipr & (1 << irq_num)) {
>              break;
>          }
>      }
>      return irq_num;
> }
> 
> instead of  (whitout loop):
> int hal_IRQ_handler(void)
> {
>      // Do hardware-level IRQ handling
>      int vector;
> 
>      vector = AIC->AIC_IVR;  // Acknoledge interupt (Reads as 0)
>      vector = AIC->AIC_ISR;  // Read interupt vector
> 
>      return vector;
> }

I'm not sure [I don't recall the reason].  Are these two methods 
equivalent?  If so, we could change it.
> 
> 
> best regards
> Ilko