I just committed the drm-next-4.14 branch to the upstream OpenChrome DRM repository. As a result, drm-next-4.13 branch is now EOL (End Of Life). No more development is planned on drm-next-4.13 branch. drm-next-4.14 branch has a lot of catching up to do with drm-next-3.19 branch since its version is at 3.0.70 right now.
drm-next-4.13 branch was an important branch since I jumped from Linux 3.19 rc6+ kernel to Linux 4.13 rc2+ kernel and eventually to Linux 4.13 rc5+ kernel. It look about 40 days to figure out why OpenChrome DRM was not working. 14 version jump is really hard for a newbie developer . . . This commit finally fixed the bug that was leading to the crash during boot time. Interestingly, a developer from Huawei got hit with the same bug, and I will imagine that he was doing the same thing I was doing (i.e., porting an old DRM to a new Linux kernel). I knew about this flaw since September 2017, and during XDC2017, I told one major AMD developer present that I was planning to contact another AMD developer who appears to be the author of commit (ea642c3216cb2a60d1c0e760ae47ee85c9c16447) that caused this callback table null pointer reference bug. I forgot to send a “strongly worded” e-mail to this AMD developer. At least the bug will now be fixed with Linux 4.16 kernel. Perhaps, I can still send it, but it will not be so strongly worded anymore.
Going back to drm-next-4.14 branch, probably within a week, it will be updated to drm-next-4.15 branch, and drm-next-4.14 branch will be EOL instantly. I do realize that OpenChrome DRM’s drm-next-4.xx branch is still not on the correct Linux kernel (since the drm-next-4.14 is on Linux 4.14 rc7+ kernel, it should really be called drm-next-4.16), but I got distracted with various events during November and December 2017 that I did not really update the Linux kernel the bleeding edge of OpenChrome DRM should be using. I am now trying to catch up as soon as possible so that drm-next-4.xx and drm-next-3.19 will track each other closely.