On Wed, Mar 06, 2024 at 12:19:42PM +0200, Jani Nikula wrote: > On Wed, 06 Mar 2024, gareth.yu@xxxxxxxxx wrote: > > From: Gareth Yu <gareth.yu@xxxxxxxxx> > > > > Turn on the panel from zero brightness of the last state, the panel was set > > a maximum PWM in the flow. Once the panel initialization is completed, the > > backlight is restored to zero brightness. There is a flckering generated. > > Please be more precise in describing what exactly happens and > when. Driver probe? Modeset? What restores backlight to zero brightness? > > Better yet, please file a bug at fdo gitlab, attach full dmesg with > debugs, etc. > > Before we had the concept of minimum brightness, the minimum was always > 0. And the check was: > > if (level == 0) > level = max; > > Historically, the point was, if you're enabling the display and > backlight, you don't want it to be at 0 brightness, because for most > displays that means a black screen. I think that hack was originally added becaue some silly userspace thingy was setting the backlight level to 0 on suspend/etc. and then forgetting to restore it back to a sane value afterwards. Dunno if that nonsense behaviour still persists to this day. -- Ville Syrjälä Intel
