Bug#655152: The problem with multiple "[drm:intel_prepare_page_flip] *ERROR* Prepared flip multiple times" is associated with KDE plasma desktop desktop effects
I have stated, that if I disable the "desktop effects" the problematic
"[drm:intel_prepare_page_flip] *ERROR* Prepared flip multiple times"
do not overload my logs.
That explains why I haven't seen this problem before (previously I
used the GNOME environment, but after it was upgraded a few months ago
I had to switch to KDE).
So currently I don't know if this bug is associated with kernel, with
KDE or with Intel drivers?
Anyway the problem does not appear on my other machines with Intel
graphic chipsets (but newer than 865G).