How to disable IRQ to stop occuring uart_evt_handler() for a short time

Question

After I process some data (command) received by UART fifo module (I have installed handler for APP_UART_DATA_READY) I need to do a short atomic operation of a few instructions. What is the best way to disable interrupt(s) in this case?
Is NVIC_DisableIRQ(UART0_IRQn) or sd_nvic_DisableIRQ(UART0_IRQn) enough?
Or can I use sd_nvic_critical_region_enter() / exit - afaik this disable some other IRQs that I don't care...

Ole Morten · Accepted Answer

As far as I understand your question, either of those should be usable. sd_nvic_DisableIRQ() will disable just the UART IRQ, while sd_nvic_critical_region_enter()/_exit() will protect the region against any application interrupt. Depending on what you actually want to achieve, either may make sense. 
 Beware that there is a macro wrapping sd_nvic_critical_region_enter() called CRITICAL_REGION_ENTER() in app_util.h, which can be used independent of calling context.