Yes, unfortunately the SJA1105Q does not support PAUSE frames, and the i.MX8MP
FEC isn't able to sustain 1000Mbps (only about 400ish) due to insufficient
internal bus bandwidth. It will generate PAUSE frames, but the SJA1105Q
ignores these, leading to packet loss, which is obviously worse than
restricting this link to 100Mbps. Ironically both chips are from the same
manufacturer, yet are incompatible in this regard.

Thanks for the explanation. Maybe add a comment that the bandwidth is
limited due to the lack of flow control resulting in packet loss in
the FEC.

Anything which looks odd deserves a comment, otherwise somebody will
question it....

	Andrew