SDDM and Save dialogues slow
I'm on Stretch with backports and a regular Stretch KDE installation on
a ThinkPad X1 Yoga (Skylake CPU and graphics, self compiled latest
kernel 4.14, now .122; a stock kernel 4.9 or 4.19 doesn't help).
Since some update a few weeks ago resume does wake up the screensaver
and mouse pointer, but the login box appears only after *half a minute*
or more whereas previously it was there immediately. This somewhat
defeats the purpose of Sleep and Resume. The battery no longer gets
detected, and powerdevil freezes and/or shows no options for closing the
Dolphin also takes a long time to start instead of doing so in an
instant as before, in a similar fashion Save dialogues in kwrite and
libreoffice take half a minute or more as well to appear. It used to be
a snappy dual boot machine. Windows sleep and resume works flawlessly.
Any ideas what may be causing this? Perhaps a recent BIOS update for
some SPECTRE mitigation? The latest Intel microcode of April? Some other
Debian update that is somehow but not obviously related to KDE? dmesg
shows an "incompatible lid switch or some such, but this was no problem
before (although dmesg never reported it).