I probably should have waited until I finished upgrading OpenChrome DRM code meant for Linux 4.14 rc7+ to be compilable with Linux 4.15 rc8+, but nonetheless, I pulled in Linux 4.15 rc8+, and committed it into the drm-next-4.15 branch of OpenChrome DRM upstream repository. As a result, drm-next-4.15 branch does not currently compile due to small changes made again to TTM related modules. It took me (mere) 4 hours to figure out the changes, and as I write this blog post, I am compiling Linux 4.15 rc8+ kernel in the background. I need to validate basic functionality after the new kernel port, so it might take me a day or two before I can commit the changes made to the code.
The good news here is that OpenChrome DRM is catching up to the bleeding edge of Linux kernel / DRM (Direct Rendering Manager) development. OpenChrome DRM is still a little off when it comes to using the correct version of Linux kernel for the given drm-next-x.xx branch (i.e., as of today, OpenChrome DRM’s drm-next-4.15 branch should really be called drm-next-4.17), but I should be able to remedy this in the next weeks. Anyway, I expect to move to drm-next-4.16 branch soon, and then in a few weeks, move again to drm-next-4.17 branch. Fairly soon, drm-next-4.16 or drm-next-4.17 branch will be at the same OpenChrome DRM version as the drm-next-3.19 branch (Version 3.0.71).