Ask a kernel developer

In cases where it's unclear what the message is trying to say, it's often worth finding the line that produced the message and then using "git blame" to find the commit that introduced it. Look at the commit to make sure it isn't making an irrelevant change to the line (if so, find the commit that introduced the version that got tweaked). In this case, the commit is by Dave Airlie, but also mentions two co-authors and two contributors. It's probably best to start with the maintainer, but the author of the code in question may be more able to explain it. (For that matter, the commit message may explain it well enough, so it's worth reading that.)