How to mask IRQ

[Eric Valette]

leonp at plris.com wrote:

> 	I need to mask, for example, IRQ5 interrupt from within the ISR.

You mean while handling another IRQ (e.g IRQ 4) I guess?

> 	Today's implementation seems not to allow this operation, as the ISR is 
> called from the IRQ dispatcher, which restores the mask state to the value it 
> saved before the ISR was called.
> 	The most simple decision I see, is to return the desired mask as a return 
> value from the ISR function. Thus, the dispatcher must check that the ISR 
> return value is not zero.

In the MPC860, there is a way to mask automatically other interrupts
when a dedicated interrupt occur (at least at the CPM level) I do not
remember for the SIU. Its from memory as I do not have the source handy...

In theory, the masks in the interrupt controller enables to define a set
of interrupt blocked on a per irq basis. Check the sources I think there
is a mask somewhere...



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