BSP question: nested interrupts?

Ben Gras beng at shrike-systems.com
Mon Apr 28 11:32:44 UTC 2014


Dear all,

I have a question about managing interrupts in a BSP that I have not been
able to answer satisfactorily by looking at other BSP code, nor looking
throught the documentation or googling. Or asking on the IRC channel :)

My question is: are BSPs expected to allow nested interrupts? Specifically,
must bsp_interrupt_dispatch() turn interrupts on before calling
bsp_interrupt_handler_dispatch for everything else to work properly?

Some BSPs do this, some don't. In the Beagle BSP I can do this by masking
the currently active interrupt and then enabling them at the CPU level; but
enabling all interrupts before the hw-specific handler is called won't
deassert the irq at the peripheral so I'm having trouble seeing how that
should work.

Example: if we are in a timer ISR and loop on polling the uptime ticks, do
we expect the ticks to be able to increase? I'm wondering if any of the
remaining failing tests are due to this. But also what the best shape of a
BSP is.

Thanks!
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