LLAD: A Low-Latency Active Detection Method for High-Frequency Periodic GPIO Signals in Linux

For real-time interaction with the physical world, systems communicate with peripherals by sending and receiving numerous high-frequency periodic signals through General-Purpose Input/Output (GPIO). Currently, systems operating in Linux environments respond to GPIO signals using an external hardware interrupt mechanism. However, this approach often results in high latency, which complicates the ability to meet the stringent timing requirements for periodic GPIO signal responses. Therefore, this paper proposes a Low-Latency Active Detection method(LLAD) that uses High Resolution timer with shorter interrupt routing paths in Linux. At the same time, Active detection is enabled by configuring a very short detection interval. The experimental platforms we adopted are Standard Linux and PREEMPT_RT patched Linux. Experimental results demonstrate that the LLAD is very effective in improving the latency of GPIO signal responses on these two platforms.