Ciro, you have reported "works for me" but you have not confirmed that you are actually trying to reproduce the bug. The problem occurs when using modeset=1. You do not mentioned that here or in your related answer on askubuntu
If you are not using modeset=1, which is essential for people using Optimus who want to avoid tear-free graphics, then please clarify. This bug still exists for me, on both of my ThinkPads, and also with Fedora 27.
Ciro, you have reported "works for me" but you have not confirmed that you are actually trying to reproduce the bug. The problem occurs when using modeset=1. You do not mentioned that here or in your related answer on askubuntu
If you are not using modeset=1, which is essential for people using Optimus who want to avoid tear-free graphics, then please clarify. This bug still exists for me, on both of my ThinkPads, and also with Fedora 27.