linux_dsm_epyc7002/drivers/net
Vladimir Oltean 0ba83aa037 net: dsa: sja1105: the PTP_CLK extts input reacts on both edges
It looks like the sja1105 external timestamping input is not as generic
as we thought. When fed a signal with 50% duty cycle, it will timestamp
both the rising and the falling edge. When fed a short pulse signal,
only the timestamp of the falling edge will be seen in the PTPSYNCTS
register, because that of the rising edge had been overwritten. So the
moral is: don't feed it short pulse inputs.

Luckily this is not a complete deal breaker, as we can still work with
1 Hz square waves. But the problem is that the extts polling period was
not dimensioned enough for this input signal. If we leave the period at
half a second, we risk losing timestamps due to jitter in the measuring
process. So we need to increase it to 4 times per second.

Also, the very least we can do to inform the user is to deny any other
flags combination than with PTP_RISING_EDGE and PTP_FALLING_EDGE both
set.

Fixes: 747e5eb31d ("net: dsa: sja1105: configure the PTP_CLK pin as EXT_TS or PER_OUT")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-06 15:03:14 -07:00
..
appletalk
arcnet
bonding
caif
can
dsa net: dsa: sja1105: the PTP_CLK extts input reacts on both edges 2020-05-06 15:03:14 -07:00
ethernet net: mvpp2: cls: Prevent buffer overflow in mvpp2_ethtool_cls_rule_del() 2020-05-06 14:15:46 -07:00
fddi
fjes
hamradio
hippi
hyperv hv_netvsc: Fix netvsc_start_xmit's return type 2020-05-01 15:24:46 -07:00
ieee802154
ipa
ipvlan
netdevsim
phy net: phy: DP83TC811: Fix WoL in config init to be disabled 2020-05-01 15:23:44 -07:00
plip
ppp
slip
team
usb net: usb: qmi_wwan: add support for DW5816e 2020-05-03 15:57:29 -07:00
vmxnet3
wan
wimax
wireguard
wireless
xen-netback
bareudp.c
dummy.c
eql.c
geneve.c
gtp.c gtp: set NLM_F_MULTI flag in gtp_genl_dump_pdp() 2020-05-01 15:34:09 -07:00
ifb.c
Kconfig
LICENSE.SRC
loopback.c
macsec.c net: macsec: fix rtnl locking issue 2020-05-06 14:34:38 -07:00
macvlan.c
macvtap.c
Makefile
mdio.c
mii.c
net_failover.c
netconsole.c
nlmon.c
ntb_netdev.c
rionet.c
sb1000.c
Space.c
sungem_phy.c
tap.c
thunderbolt.c
tun.c
veth.c
virtio_net.c
vrf.c
vsockmon.c
vxlan.c
xen-netfront.c