linux/drivers/net
Frank Li 031916568a net: fec: workaround stop tx during errata ERR006358
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>
2013-07-27 20:14:48 -07:00
..
appletalk
arcnet arcnet: cleanup sizeof parameter 2013-07-19 17:36:03 -07:00
bonding Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-07-03 14:55:13 -07:00
caif drivers/net: caif: fix wrong rtnl_is_locked() usage 2013-07-09 12:55:48 -07:00
can can: usb_8dev: fix urb leak on failure path in usb_8dev_start() 2013-07-19 14:55:14 +02:00
cris
dsa
ethernet net: fec: workaround stop tx during errata ERR006358 2013-07-27 20:14:48 -07:00
fddi net/fddi/skfp/skfddi: Use module_pci_driver to register driver 2013-05-22 14:35:05 -07:00
hamradio net: pass info struct via netdevice notifier 2013-05-28 13:11:01 -07:00
hippi net/hippi/rrunner: Use module_pci_driver to register driver 2013-05-22 14:35:05 -07:00
hyperv hyperv: Fix the NETIF_F_SG flag setting in netvsc 2013-07-16 23:02:24 -07:00
ieee802154 drivers/net/ieee802154: don't use devm_pinctrl_get_select_default() in probe 2013-07-11 17:18:27 -07:00
irda net: irda: remove unnecessary platform_set_drvdata() 2013-05-27 22:34:51 -07:00
phy net: sun4i: fix timeout check 2013-07-24 17:04:20 -07:00
plip
ppp net: pass info struct via netdevice notifier 2013-05-28 13:11:01 -07:00
slip
team Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-06-19 16:49:39 -07:00
usb usbnet: do not pretend to support SG/TSO 2013-07-26 13:48:22 -07:00
vmxnet3
wan Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-07-03 14:55:13 -07:00
wimax
wireless brcmfmac: bail out of brcmf_txflowblock_if() for non-netdev interface 2013-07-22 16:04:09 -04:00
xen-netback xen-netback: xenbus.c: use more current logging styles 2013-07-02 00:52:55 -07:00
dummy.c dummy: fix oops when loading the dummy failed 2013-07-11 11:59:20 -07:00
eql.c
ifb.c ifb: fix oops when loading the ifb failed 2013-07-11 12:00:05 -07:00
Kconfig packet: nlmon: virtual netlink monitoring device for packet sockets 2013-06-24 16:39:05 -07:00
LICENSE.SRC
loopback.c
macvlan.c macvtap: Let TUNSETOFFLOAD actually controll offload features. 2013-06-25 16:44:56 -07:00
macvtap.c macvtap: do not zerocopy if iov needs more pages than MAX_SKB_FRAGS 2013-07-18 13:04:25 -07:00
Makefile packet: nlmon: virtual netlink monitoring device for packet sockets 2013-06-24 16:39:05 -07:00
mdio.c
mii.c
netconsole.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2013-07-09 18:24:39 -07:00
nlmon.c nlmon: use standard rtnetlink link api for add/del devices 2013-07-02 12:53:17 -07:00
ntb_netdev.c ntb_netdev: remove from list on exit 2013-05-15 10:58:14 -07:00
rionet.c rapidio/rionet: rework driver initialization and removal 2013-07-03 16:08:04 -07:00
sb1000.c
Space.c
sungem_phy.c
tun.c tuntap: do not zerocopy if iov needs more pages than MAX_SKB_FRAGS 2013-07-18 13:04:25 -07:00
veth.c veth: add vlan features 2013-07-19 17:36:03 -07:00
virtio_net.c No real surprises. 2013-07-10 14:50:58 -07:00
vxlan.c vxlan: fix igmp races 2013-07-19 17:07:25 -07:00
xen-netfront.c xen-netfront: pull on receive skb may need to happen earlier 2013-07-17 12:51:19 -07:00