[ECOS] isr() and dsr() running environment?

[Peter Vandenabeele]

On Mon, Oct 21, 2002 at 03:44:55PM +0100, Nick Garnett wrote:
> <jameshq@liverpool.ac.uk> writes:
> 
> > Thanks a lot. 
> > 
> > How if DSR1() interrupted by ext_IRQ2, when ISR2( ) exit how does
> > DSR1( ) resume?  as the flow diagram(is the following flow diagram
> > correct?):
> > 
> > ext_IRQ1 --> ISR1() --> DSR1() --> interrupted by ext_IRQ2 --> ISR2()
> > --> call interrupt_end() --> call pending DSRs but now DSR2 won't run
> > here because DSR1 not finished yet. (right?)
> 
> Not quite. Since the scheduler lock is >1 here, unlock_inner() will
> not even try to run DSRs.
> 
> > --> return from ext_IRQ1
                           ^
			   2 ??
			   
    (ISR1() was already fully finished before DSR1() even started ?)

> > --> back to interrupted DSR1( ) and continues excution --> exit from
> > DSR1( ) --> still in Cyg_Interrupt::call_pending_DSRs_inner(void)
> > because DSR2 still not run --> run DSR2( ) --> finish DSR2( ) -->
> > return from ext_IRQ1 VSR (e.g Sparc target it returns from the call to
> > "hal_default_interrupt_vsr" when the time ext_IRQ1 happens.) 

Peter

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