On Mon, Aug 25, 2014 at 11:26:19AM +0200, Stefan Roese wrote:
We noticed on the DXR2 platform (AM335x with a SMSC LAN9303 switch connected to the CPSW MAC) that the network performance in U-Boot is quite poor. Only when the transfer is started without a cable connected, and the cable is plugged after the first timeout "T" occured, an increased in performance can be seen. Debugging has revealed, that the cpsw driver has constant link checking builtin into the rx and tx functions. This results in the bad performance and seems to be unnecessary. The link has already been checked in the init function, before the transfer is started. This usually is sufficient.
BTW: I have seen no other network driver in U-Boot so far, that constantly checks for link in the rx / tx functions.
Yes, this strongly feels like a bring-up sanity check thing that was left in by accident.