Hi, On Fri, 26 Jun 2020 at 10:00, Pekka Paalanen <ppaalanen@xxxxxxxxx> wrote: > On Thu, 25 Jun 2020 12:44:36 +0200 Daniel Vetter <daniel@xxxxxxxx> wrote: > > Maybe an aside, but the guideline is for autoconfiguration: > > - Light up everything that has connector status connected. > > - If nothing has that status, try to light up the connectors with > > status "unknown". > > > > This is only really relevant on older platforms, mostly for VGA and > > somewhat for dvi outputs. > > > > Maybe another thing we should put down somewhere in the uapi docs ... > > As I had no idea what "unknown" means or when it can happen, I assumed > that it must mean "the hardware cannot know". If the hardware cannot > know, then I certainly will not be trying to enable that, unless > explicitly configured to do so. Having a phantom output is worse than > having a real output that does not light up, because it's not obvious at > first with phantom output that anything is wrong. You may just be > wondering where your windows disappear, or where did you mouse cursor > go, or why you see a wallpaper but no login dialog, etc. How about a refinement of Dan's suggestion, proceeding down this logical order and breaking if true: - ignore all disconnected outputs - if any outputs are connected, ignore all unknown outputs - if only one output is unknown, use only that output (with default mode if need be) - if any outputs are unknown but have EDID present, use only those outputs - at this point, we have multiple unknown outputs with no EDID - break and demand explicit user configuration Cheers, Daniel
