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properly handling arm FIQ
- From: "Dan Conti" <danc at fullplaymedia dot com>
- To: "Ecos-Discuss (E-mail)" <ecos-discuss at sources dot redhat dot com>
- Date: Fri, 2 Aug 2002 12:20:20 -0700
- Subject: [ECOS] properly handling arm FIQ
Hi,
I seem to be missing something about how irqs and fiqs are handled in ecos on an arm7, hopefully someone can enlighten me.
1) i'm noticing that in the FIQ handler in vectors.S, it masks IRQs. my fiq handler doesn't do this - is it actually possible for a standard IRQ to interrupt a FIQ?
2) i'm also noticing that in the IRQ handler in vectors.S it masks FIQs, same as HAL_DISABLE_INTERRUPTS(). that is, unless you build the i2s_audio_test for edb7xxx, where hal_disable_interrupts is redefined to not mask off the fiq. any potential harm in changing the IRQ handler to leave the FIQ alone?
it seems like the fiq should be uninterruptable, but should be allowed to interrupt standard interrupts.
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