在自己的板子上
移植的版本：
uboot K2_UBOOT_2013_01_15.02_02
linux K2_LINUX_03.10.10_14.12
硬件：直接从dsp中引出万兆接口，采用mac to mac 模式（没PHY），接SFP+模块，通过光纤(30cm)与PC连接。在PC显示该网络链路为10Gbps
启动内核后万兆输出如下：
[ 36.773207] keystone-netcp 2090000.netcp: dma_chan_name nettx2
[ 36.779766] keystone-netcp 2090000.netcp: Created interface "eth3"
[ 36.785971] keystone-netcp 2090000.netcp: dma_chan_name nettx3
[ 36.792000] XGE serdes config:
[ 36.795061] ref_clk=156.25MHz, link_rate=10.3125G, lanes=2
[ 36.800742] c1=2, c2=0, cm=2, tx_att=12, tx_vreg=4
[ 36.805720] eq flags: vreg=1, cdfe=1, offset=1
[ 36.810357] XGE: serdes reset
[ 37.941733] XGE: timeout waiting for serdes link up
[ 37.946970] keystone-netcp 2f00000.netcp: Created interface "eth4"
[ 37.953182] keystone-netcp 2f00000.netcp: dma_chan_name xgetx0
[ 37.959042] XGE: serdes reset
[ 39.191584] XGE: timeout waiting for serdes link up
[ 39.196805] keystone-netcp 2f00000.netcp: Created interface "eth5"
[ 39.203018] keystone-netcp 2f00000.netcp: dma_chan_name xgetx1
[ 39.208879] XGE: serdes reset
[ 40.441386] XGE: timeout waiting for serdes link up
[ 40.446323] keystone-netcp 2090000.netcp: pdsp 0 firmware: keystone/pa_pdsp0_classify1.fw
[ 40.454534] keystone-netcp 2090000.netcp: pdsp 1 firmware: keystone/pa_pdsp1_classify1.fw
[ 40.462744] keystone-netcp 2090000.netcp: pdsp 2 firmware: keystone/pa_pdsp2_classify1.fw
[ 40.470954] keystone-netcp 2090000.netcp: pdsp 3 firmware: keystone/pa_pdsp3_classify2.fw
[ 40.479164] keystone-netcp 2090000.netcp: pdsp 4 firmware: keystone/pa_pdsp45_pam.fw
[ 40.486934] keystone-netcp 2090000.netcp: pdsp 5 firmware: keystone/pa_pdsp45_pam.fw
1：关于万兆serdes 没有link up 是否影响网络传输速度
2：使用iperf （版本2.0.5）进行万兆测试 TCP模式下最多达到128MB/s,udp模式下最多达到252MB/s
本应该设置MTU 为9216，结果程序自动改为536，得出以上速度
root@k2hk-evm:~# iperf -c 192.168.4.1 -i 1 -f MB -P 2 -M 9216 -l 1048576 -w 20M
WARNING: attempt to set TCP maximum segment size to 9216, but got 536
WARNING: attempt to set TCP maximum segment size to 9216, but got 536
------------------------------------------------------------
Client connecting to 192.168.4.1, TCP port 5001
TCP window size: 0.31 MByte (WARNING: requested 20.0 MByte)
------------------------------------------------------------
请问会有什么原因导致万兆实际速度相差这么大
