Re: interrupt handler in arm question

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FIQ exception is not implemented in Linux Kernel. Actually, when ARM CPU takes FIQ exception, it branches to 0xffff001c address, which contains the below code from entry-armv.S: vector_fiq:        disable_fiq        subs    pc, lr, #4

Now, disable_fiq not implemented for all the platforms. But, anyway, 'subs pc, lr, #4' returns the CPU to the point where FIQ exception has happened and the system continues to run as usual.

As you said, disable_fiq is empty in OMAP architecture. .macro  disable_fiq .endm

So from the above explanation,I can saythat LINUX is not making use of FIQ feature of arm.Am I right?

Absolutely. --- Kosta