Comment # 16 on bug 1185601 from Takashi Iwai

(In reply to Wolfgang Wander from comment #15)
> (In reply to Takashi Iwai from comment #14)
> > OK, then could you fiddle with i915.enable_dpcd_backlight=xxx boot option?
> > Pass 0, 1, 2 or 3 to xxx.
> 
> 0: no change
> 1: no change
> 2: no change
> 3: no change
> 
> in all cases the backlight comes on, but the screen itself stays black.

Aha, and this was so even without the option, right?

> Do you want dmesgs of these attempts, with drm.debug=0x1e? And if so, with
> the SuSE kernel or the vanilla 5.12.0?

Not urgently needed, so far.  I still need to read down the previous logs.

But, more urgently needed is the report to upstream.  If not done yet, care to
do it?  Please tell us the issue URL, so that we can track there.