So far I only successfully applied the PREEMPT_RT patch on Release 1.6 which was released years ago. Just wondering could anyone share their experience for applying similar patch on the current Release 2.1? I'm still pondering upon the build failure since the kernel version is the same though.
Which are the source files you are using? Are you using the patch from these files or are you getting it from another place?
Which kernel version are you getting and which is the one you want to get?
Please let us know if you are having other errors while building the image.