To handle application in the Linux userspace in hard realtime the current LINUX kernel 4.9.88 must be patched.
This is because LINUX does not include all realtime patches from the PREEMT RT version (which is the preferred realtime implementation from LINUX Kernel developers). Newer kernel will less differ from a fully PREEMPT RT kernel version.
So, how do we have to patch the Kernel from the efusA9X release to gain full realtime support?