On Wed, Feb 27, 2019 at 01:16:27PM +0200, Jani Nikula wrote: > On Wed, 27 Feb 2019, Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx> wrote: > > One thing that this series does not consider is the DP lane count > > problem. The GPU drivers (i915 in this case) does not know is four, > > two or one DP lanes in use. > > Also, orientation. > > > I guess that is not a critical issue since there is a workaround (I > > think) where the driver basically does trial and error, but ideally we > > should be able to tell i915 also the pin assignment that was > > negotiated with the partner device so it knows the DP lane count. > > Yeah, if the information is there, we'd like to know. With the > orientation, there's a worst case of sixth attempt of finding out > there's just one lane in a certain orientation. Couple that with link > rate selection (did it not work because too high link rate or because > the lanes are just not there?) we get pretty confused about what we > should try. The orientation is also considered in the alt mode API. We have a function for that typec_altmode_get_orientation(), but it of course requires that the caller has a handle to the alt mode object. So basically we would again need tight coupling between the DP connector and USB Type-C connector. Hans, I'm not so sure we should, or can, rule out the "tight coupling" option after all. thanks, -- heikki _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
