02-12-2020 03:20 AM
Our board is based on the Zynq Ultrascale+ MPSoC. We use the DP to interface to an LVDS panel via a DP-LVDS bridge (PTN3460). As we are left without pins on the PS, we chose not to route the DP AUX channel, as we are using an embedded panel of which we know the parameters in advance.
Now we are trying to wake up the board and, reviewing the VESA 1.2 spec, we see that it assumes that the AUX channel is always present; it is not clear if it can be removed if its functions are unused (i.e. link training).
I.e, in the linux driver the channel is used for retrieving EDID parameters or do the training. We can skip that since we have control of the sink, but the question arises wether it can bring any other problems, as I see the channel is registered for other layers to use it, I suppose the dp common one.
So, the question would be, is it feasible to use a DP without AUX channel at all?
04-17-2020 12:18 AM
We finally routed the AUX channel through the PL. At least with our bridge it wasn't possible to go without it. Maybe with other chips, see the question I posted on stackexchange . Anyway, I have my doubts. I explain it in my comment on the that stackexchange post.