[Intel-gfx] Intel drm "Atomic update failure"

[Janne Heikkinen]

I've been experiencing system hangs with 4.2 release candidate kernels
on Asus X553MA laptop. 4.1.0 seems stable. I've set serial console
via ttyUSB0 so that I might be able to get some clue what might cause
the hangs.

With 4.2-rc7 (SHA 1b647a166f07dcf08709c8606470f4b17a4aa11d)
I got the following:

[ 4102.375874] [drm:intel_pipe_update_end [i915]] *ERROR* Atomic
update failure on pipe A (start=246190 end=246191)

[ 7657.317892] [drm:intel_pipe_update_end [i915]] *ERROR* Atomic
update failure on pipe A (start=459302 end=459303)

But the system didn't actually hang during the test when those messages
appeared.

Sometimes the hang might happen few minutes after booting and
sometimes it might take few hours. I've now tried few times running
with serial console and so far got only those two error messages.
And there was also few hangs but I didn't get anything on
console with them.