Re: [ECOS] Re: DSR question

["Tim Michals" <t dot michals at attbi dot com>]

> > yes this is what is happening, the DSR unmasks the
> > interrupt causing the the ISR to retrigger before the
> > DSR is completed.  So this can cause a deadlock issue?
> > I thought this should just retrigger the DSR again?
>
> While in theory eCos should be able to handle this, it is not really
> designed to deal with it. The exact behaviour is undefined.
>
> Depending on things like exactly where in the ISR and DSR the
> interrupt mask and unmask come, it is possible for a continuously
> interrupting source to stack up frames and maybe overflow the
> interrupt stack. This is the most likely cause of your problems.
>
One last question, sorry to keep going on...  This also could happen if
multple sources were triggering at the same time?  Of if the DSR is slow to
processing the interrupt?  Just want to make sure to try to void this as
much as possible.
>
> --
> Nick Garnett - eCos Kernel Architect
> http://www.eCosCentric.com/
>


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