When installing Deepin 15.4.1 on my HP 550 laptop. I followed the steps given at https://www.deepin.org/en/installation/ up until the 9th step perfectly and everything worked fine.
When I hit experience it reboots and displays a message that reads out
[  11.99606] [drm:drm_atomic_helper_commit_cleanup_done [drm_kms_helper]] *ERR
OR* [CRTC:26:pipe A] flip_done timed out
[  24.540073] [drm:drm_atomic_helper_commit_cleanup_done [drm_kms_helper]] *ERROR* [CRTC:26:pipe A] flip_dome timed out

BusyBox v1.22.1 (Debian 1:1.22.0-19+b2) built-in shell (ash)
Enter 'help' for a list of built-in commands.

(initramfs) _