Comment 16 for bug 1453593

at #15:
one time boot with 3.19.0-17:

added 'drm.debug=0xe' to the boot options, removed "quiet no splash".
Boot attempt with 3.19.0-17 was made at 10:56, I suppose.

Later, successfully booted was with 4.0.
Included /var/log/kern.log.