On Thu, 07 Mar 2013 17:17:19 +0200, Kevin Wilson said: > Does this mean that once you are disabling > interrupts, these interrupts are lost ? even later, when we will > enable interrupts, the interrupts from the past that should have been > created (but interrupts were disabled at that time interval) are in > fact lost?
Level-triggered interruots will go off once interrupts are re-enabled, assuming that the device has kept the level set and not given up and timed out. Edge-trittered interrupts are gone. That's part of why most hardware doesn't use edge triggers - it's just too hard to guarantee proper device driver operation. Also, in common usage, "disabled interrupts" means that you're not listening to *any* interrupts, while "masked" means "we're not listening to *this* interrupt source, even if we *are* accepting interrupts from other sources". The difference is that sometimes the CPU is doing stuff that it would be potentially screwed if *any* interrupt happened, so we disable them. Other times we're busy inside a device driver, and we're in a critical section for that device - but it's safe for other devices to interrupt. So to improve latency we mask off just the one interrupt not all of them.
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