031916568a
If the ready bit in the transmit buffer descriptor (TxBD[R]) is previously detected as not set during a prior frame transmission, then the ENET_TDAR[TDAR] bit is cleared at a later time, even if additional TxBDs were added to the ring and the ENET_TDAR[TDAR] bit is set. This results in frames not being transmitted until there is a 0-to-1 transition on ENET_TDAR[TDAR]. Workarounds: code can use the transmit frame interrupt flag (ENET_EIR[TXF]) as a method to detect whether the ENET has completed transmission and the ENET_TDAR[TDAR] has been cleared. If ENET_TDAR[TDAR] is detected as cleared when packets are queued and waiting for transmit, then a write to the TDAR bit will restart TxBD processing. This case main happen when loading is light. A ethernet package may not send out utile next package put into tx queue. How to test: while [ true ] do ping <IP> -s 10000 -w 4 ping <IP> -s 6000 -w 2 ping <IP> -s 4000 -w 2 ping <IP> -s 10000 -w 2 done You will see below result in overnight test. 6008 bytes from 10.192.242.116: seq=1 ttl=128 time=0.722 ms 4008 bytes from 10.192.242.116: seq=0 ttl=128 time=1001.008 ms 4008 bytes from 10.192.242.116: seq=1 ttl=128 time=1.010 ms 10008 bytes from 10.192.242.116: seq=0 ttl=128 time=0.896 ms After apply this patch, >1000ms delay disappear. Signed-off-by: Frank Li <Frank.Li@freescale.com> Acked-by: Fugang Duan <B38611@freescale.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
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.. | ||
appletalk | ||
arcnet | ||
bonding | ||
caif | ||
can | ||
cris | ||
dsa | ||
ethernet | ||
fddi | ||
hamradio | ||
hippi | ||
hyperv | ||
ieee802154 | ||
irda | ||
phy | ||
plip | ||
ppp | ||
slip | ||
team | ||
usb | ||
vmxnet3 | ||
wan | ||
wimax | ||
wireless | ||
xen-netback | ||
dummy.c | ||
eql.c | ||
ifb.c | ||
Kconfig | ||
LICENSE.SRC | ||
loopback.c | ||
macvlan.c | ||
macvtap.c | ||
Makefile | ||
mdio.c | ||
mii.c | ||
netconsole.c | ||
nlmon.c | ||
ntb_netdev.c | ||
rionet.c | ||
sb1000.c | ||
Space.c | ||
sungem_phy.c | ||
tun.c | ||
veth.c | ||
virtio_net.c | ||
vxlan.c | ||
xen-netfront.c |