Boot very slow because of drm_kms_helper errors

Question

I just installed 16.04 on my MacBook Air, and everything seems to work well, except booting the system. I've been going through the dmesg-log and found out that drm_kms_helper-errors occur repeatedly and takes a lot of time each. The excact error is like this:

[drm:drm_atomic_helper_commit_cleanup_done [drm_kms_helper]] *ERROR* [CRTC:26:pipe A] flip_done timed out

The CRTC-value and the pipe-value varies, but otherwise all the errors are identical.

What does this mean and how do I fix it? If it can't be fixed, how do I prevent it from using so much time when booting?

Answer 1

This is a bug. To avoid delay you can use workaround. From terminal run:

1. sudo nano /etc/default/grub

Then add the kernel boot parameter: video=SVIDEO-1:d, so it will look like this: GRUB_CMDLINE_LINUX_DEFAULT="quiet splash video=SVIDEO-1:d"

2. sudo update-grub
3. sudo reboot