suspend/resume regression

[Theron]

> Hi!
> I'm also seeing issues, not as severe as Pete, but after I resume 
> (which works, with drm-next and DMC firmware), the system becomes 
> sluggish.  It feels like I/O takes more time, and graphics are 
> sluggish (very sientific, I know, but for instance git operations are 
> much slower after a resume).  I know there's been an update to acpica 
> between my system updates, when this started to happen, but I haven't 
> had time to revert that update and test again.  I will try to do that 
> and report back.
> Regards
Hi Niclas,
I used drm-next on Skylake with issues which sound similar. Resuming 
from suspend, or simply switching the laptop display output off and on 
from xrandr, resulted in graphics sluggishness (drop to 30fps in 
glxgears) and graphical corruption in Xorg apps, which persisted even 
after restarting these apps.  Switching to drm-stable made the problems 
go away; I haven't had time to figure out what -next is doing 
differently to cause them.

Pete's issue sounds more severe, and unrelated as it happens without drm 
loaded.  My kernel is two weeks out of date (r333093), so I need to 
check whether the more recent changes affect my system as well.

Theron