Essentially, I'm trying to connect a source with only two HBR2 lanes to a device that requires four HBR1 lanes. Theoretically, the bandwidth is there. But what kind of an IC would I need to accomplish this?
Redrivers seem to only refresh the signal, they won't convert it.
Demuxers simply act as relay switches; they don't actually touch the signal itself.
It seems like most DP to DP++ converter ICs (where the intention is to support HDMI or DVI output) will only act as a redriver when outputting via DP, so that doesn't really help me, either.
All I've found is this converter, which might be what I'm looking for, but I can't really figure out if it will actually convert from two to four lanes, or will just refresh the signal. It's also BGA, and I would much rather prefer a QFP or QFN.
To give a little more insight into the use case: I've got an eDP source with two eDP 1.2-compliant lanes that support up to HBR2, and I'm trying to connect it to a 2560x1440 (@60Hz) eDP panel that requires 4-lane HBR1. I've already tried connecting with just two HBR2 lanes and it didn't establish a connection; I'm not entirely sure if the DP spec requires the implementation of lane reduction the way PCI-E does, or if my panel just doesn't support eDP 1.2, but either way it isn't working.