https://bugzilla.kernel.org/show_bug.cgi?id=83331
--- Comment #7 from Klaus Kusche klaus.kusche@computerix.info --- 1.) The behaviour is absolutely reproducible: I *always* get almost exactly the same delays (both during boot and during internal display output off / on), I *always* get exactly the same messages, and I *always* get a non-functional internal display with strange patterns after dpms standby/suspend/off (external displays are fine).
The only random thing is that during boot the internal display sometimes is cleanly black for 5 seconds on the VGA->fbcon switch, and sometimes shows some white flashes at the beginning of this 5 second period.
2.) Internal display output off / on does not produce any kernel messages, the delay happens silently.
3.) I'll attach a kernel boot log with printk timings: Radeon, drm and fbcon init start at 2.35 and end at 7.77 (which is 60 % of the whole kernel boot time) * There is a 0.5 sec delay before the ring tests. * ... and a 1.5 sec delay before "fb mappable" * ... and a 3.0 sec delay before switching to fbcon