I profiled our drivers transmit routine. It looks there are large delays when DMA. The kdiff values are in nanoseconds from the time I call cpdma_chan_submit, till the tx_handler is called. The bytes is the number of bytes in the dma. the times have outliers in the 6572650 range. I would be interested to know if there has been a patch or fix to this. thanks.
K-
root@touchlink-9059af3cfac8:~# /media/sdb1/main 10 192.168.0.1
[ 196.010000] cpsw_tx_handler:684 dma diff 0 kdiff 55600 bytes 1502
[ 196.020000] cpsw_tx_handler:684 dma diff 0 kdiff 27750 bytes 1502
[ 196.030000] cpsw_tx_handler:684 dma diff 0 kdiff 43450 bytes 1502
[ 196.040000] cpsw_tx_handler:684 dma diff 0 kdiff 27400 bytes 1502
[ 196.060000] cpsw_tx_handler:684 dma diff 0 kdiff 45450 bytes 1502
[ 196.060000] cpsw_tx_handler:684 dma diff 0 kdiff 28100 bytes 1502
[ 196.070000] cpsw_tx_handler:684 dma diff 0 kdiff 40900 bytes 1502
[ 196.080000] cpsw_tx_handler:684 dma diff 6 kdiff 6572650 bytes 1502
[ 196.110000] cpsw_tx_handler:684 dma diff 0 kdiff 48050 bytes 1502
[ 196.110000] cpsw_tx_handler:684 dma diff 0 kdiff 27450 bytes 1502
end 1395019098 nsec 739626850 start 1395019098 nsec 642101350
pack 10 bytes 14600 bits 116800 ms 97525 pac 9752 bytes 0
root@touchlink-9059af3cfac8:~# /media/sdb1/main 10 192.168.0.1
[ 214.400000] cpsw_tx_handler:684 dma diff 0 kdiff 51800 bytes 1502
[ 214.400000] cpsw_tx_handler:684 dma diff 0 kdiff 29800 bytes 1502
[ 214.410000] cpsw_tx_handler:684 dma diff 0 kdiff 43700 bytes 1502
[ 214.420000] cpsw_tx_handler:684 dma diff 6 kdiff 6580201 bytes 1502
[ 214.440000] cpsw_tx_handler:684 dma diff 0 kdiff 49550 bytes 1502
[ 214.440000] cpsw_tx_handler:684 dma diff 0 kdiff 28250 bytes 1502
[ 214.450000] cpsw_tx_handler:684 dma diff 0 kdiff 29800 bytes 1502
[ 214.470000] cpsw_tx_handler:684 dma diff 0 kdiff 38550 bytes 1502
[ 214.470000] cpsw_tx_handler:684 dma diff 0 kdiff 29550 bytes 1502
[ 214.480000] cpsw_tx_handler:684 dma diff 0 kdiff 35150 bytes 1502
end 1395019144 nsec 229010251 start 1395019144 nsec 147718950
pack 10 bytes 14600 bits 116800 ms 81291 pac 8129 bytes 0
root@touchlink-9059af3cfac8:~# /media/sdb1/main 10 192.168.0.1
[ 218.580000] cpsw_tx_handler:684 dma diff 0 kdiff 50050 bytes 1502
[ 218.590000] cpsw_tx_handler:684 dma diff 0 kdiff 46750 bytes 1502
[ 218.590000] cpsw_tx_handler:684 dma diff 0 kdiff 28200 bytes 1502
[ 218.600000] cpsw_tx_handler:684 dma diff 0 kdiff 37650 bytes 1502
[ 218.610000] cpsw_tx_handler:684 dma diff 6 kdiff 6562350 bytes 1502
[ 218.620000] cpsw_tx_handler:684 dma diff 0 kdiff 42200 bytes 1502
[ 218.620000] cpsw_tx_handler:684 dma diff 6 kdiff 6532700 bytes 1502
[ 218.630000] cpsw_tx_handler:684 dma diff 0 kdiff 40300 bytes 1502
[ 218.640000] cpsw_tx_handler:684 dma diff 6 kdiff 6542050 bytes 1502
[ 218.640000] cpsw_tx_handler:684 dma diff 0 kdiff 33250 bytes 1502
end 1395019148 nsec 394431599 start 1395019148 nsec 327564051
pack 10 bytes 14600 bits 116800 ms 66867 pac 6686 bytes 0
