Part Number:OMAP-L138
Tool/software: Linux
It seems that by default the OMAP-L138 didn't have PREEMPT_RT support in the Linux SDK 04.01.00.06 version.
I appended the linux-ti-staging-rt_4.9.bb recipe to include the "real_time.cfg" config for the LCDK (core-image-minimal and rt-tests package).
After running the cyclictest tool (cyclictest -l100000000 -m -Sp90 -i200 -h100000 -q >output) and plotting the latency graph (https://www.osadl.org/Create-a-latency-plot-from-cyclictest-hi.bash-script-for-latency-plot.0.html) I realized that the real-time performance, in terms of latency, is pretty bad. I compared the same Linux SDK with the beaglebone black (core-image-minimal and rt-tests package) and the results are much more satisfactory.
I decided to compare the branches "ti-rt-linux-4.9.y" and "ti-lsk-linux-4.9.y" and nothing specific to the SoC (or cpu core) came with to explain this huge difference of the rt performance.
I'm just wondering if I'm losing something specific to the kernel configuration and/or what piece of code related to davinci/da8050 needs to be modified to achieve the same level of determinism.