Hi,
I guess you are using NIOS IDE/EDS 9.1 or higher?
My assumption is that you are using the ENHANCED Interrupt API which doesn't implement
alt_irq_interruptible()/alt_irq_non_interruptible() anymore.
The only way I know (means not that there is not an other way) how to use the both functions, is to manually change ALT_ENHANCED_INTERRUPT_API_PRESENT in system.h to ALT_LEGACY_INTERRUPT_API_PRESENT. Every time you regenerate your BSP or syslib you have to change it again!
But that's just a workaround.
I had the same problems and then included the VIC as EIC in my design. You can use the VIC with ENHANCED API. But much better, the VIC can handle the i
nterruptible stuff without changing your code. That means your ISRs are interruptible without a call to
alt_irq_interruptible(). Disadvantage: Until the momen, I don't know how set the option that an IRQ is not interruptible.