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FEC pause frame generation on imx6solox

Question asked by Abhishek Pandit on Feb 27, 2018
Latest reply on Feb 27, 2018 by igorpadykov

Does the FEC generate pause frames with a non-zero duration on imx6 solox? (i.e. is the pause_duration 2-byte value set to anything)


- Kernel: linux-fslc 4.1-1.0.x-imx

- Hardware: Custom board based off imx6solox_sabresd


We're running an ethernet throughput test with an Ixia traffic generator and in the packet captures, I noticed that we were getting pause frames with a duration of 0.


I checked that we are enabling pause frames with ethtool:

$ ethtool -a eth0
Pause parameters for eth0:
Autonegotiate:  on
RX:             on
TX:             on


I also looked at drivers/net/ethernet/fec_main.c and it looks like we should be writing 0xFFF0 to it (which is non-zero).


I tried to capture packets with tcpdump on my desktop but it seems the pause frames were being filtered out (macc.opcode = 0x1 wasn't showing anything on wireshark).