On Wed, Nov 08, 2017 at 02:21:08PM -0800, Eric Anholt wrote: > Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> writes: > > > On Wed, Nov 08, 2017 at 12:17:28PM -0800, Eric Anholt wrote: > >> Ville Syrjala <ville.syrjala@xxxxxxxxxxxxxxx> writes: > >> > >> > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > >> > > >> > Apparently some sinks look at the YQ bits even when receiving RGB, > >> > and they get somehow confused when they see a non-zero YQ value. > >> > So we can't just blindly follow CEA-861-F and set YQ to match the > >> > RGB range. > >> > > >> > Unfortunately there is no good way to tell whether the sink > >> > designer claims to have read CEA-861-F. The CEA extension block > >> > revision number has generally been stuck at 3 since forever, > >> > and even a very recently manufactured sink might be based on > >> > an old design so the manufacturing date doesn't seem like > >> > something we can use. In lieu of better information let's > >> > follow CEA-861-F only for HDMI 2.0 sinks, since HDMI 2.0 is > >> > based on CEA-861-F. For HDMI 1.x sinks we'll always set YQ=0. > >> > > >> > The alternative would of course be to always set YQ=0. And if > >> > we ever encounter a HDMI 2.0+ sink with this bug that's what > >> > we'll probably have to do. > >> > >> Should vc4 be doing anything special for HDMI2 sinks, if it's an HDMI1.4 > >> source? > > > > As long as you stick to < 340 MHz modes you shouldn't have to do > > anything. For >=340 MHz you'd need to use some new HDMI 2.0 features. > > > > Looks like vc4 crtc .mode_valid() doesn't do much. I presume it's up > > to bridges/encoders to filter out most things that aren't supported? > > I had a patch for that at > https://patchwork.freedesktop.org/series/30680/ -- fedora folks had run > into trouble with 4k monitors. Ack on the clock limiting patch, silly that it's stuck. No idea about CEC, better for Hans/Boris I guess. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch