Mats and Nemanja give good information about the delay of interruption . There are two - another problem that I would add to the three indicated by the Mats.
- Other simultaneous / close simultaneous interrupts.
- OS delay due to masking interrupts. Edit: This is an answer to the mats, just not explained.
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mrs r9, cpsr
biceq r9, r9,
arch/arm/include/asm/irqflags.h Linux , . A :
lock interrupts;
manipulate some flag in struct;
unlock interrupts;
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