Michael Brown
77afdc5643
[realtek] Use explicit value for TCR.MXDMA
Some RTL8169 cards (observed with an RTL8169SC) power up with
TCR.MXDMA set to 16 bytes. While this does not prevent proper
operation, it almost certainly degrades performance.
Fix by explicitly setting TCR.MXDMA to "unlimited".
Signed-off-by: Michael Brown <mcb30@ipxe.org>