Hello there. I am using 4.9.11 with rt9 on ARM imx6 soc. I am writing a device driver and I noticed that my first run of my driver gives big latency - in the region on 10msec. When I get a gpio interrupt, I schedule some work and the user waiting on a read() takes reply in about 10,30msec, on the second run it gets latency down to 140usec. I changed the tick from 100Hz to 300Hz and 500Hz, I noticed that my starting latency was dropped to 3400usec and 2320usec respectively. Which indicate some delays to kickoff for first time the scheduled work related to the granularity of the timer tick. Any ideas of what may be wrong? Thanks Andy
