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authorVladimir Oltean <vladimir.oltean@nxp.com>2019-11-14 17:03:25 +0200
committerDavid S. Miller <davem@davemloft.net>2019-11-15 12:32:16 -0800
commitba551bc3bc22f3a9f16a31cd856b823e76489009 (patch)
tree3df385dbe165760a86d3ea260f6fa74e5df52df4 /drivers/net/ethernet/mscc/ocelot.c
parentnet: mscc: ocelot: export a constant for the tag length in bytes (diff)
downloadlinux-dev-ba551bc3bc22f3a9f16a31cd856b823e76489009.tar.xz
linux-dev-ba551bc3bc22f3a9f16a31cd856b823e76489009.zip
net: mscc: ocelot: adjust MTU on the CPU port in NPI mode
When using the NPI port, the DSA tag is passed through Ethernet, so the switch's MAC needs to accept it as it comes from the DSA master. Increase the MTU on the external CPU port to account for the length of the injection header. Without this patch, MTU-sized frames are dropped by the switch's CPU port on xmit, which is especially obvious in TCP sessions. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/mscc/ocelot.c')
-rw-r--r--drivers/net/ethernet/mscc/ocelot.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/net/ethernet/mscc/ocelot.c b/drivers/net/ethernet/mscc/ocelot.c
index 8b73d760dfa5..42da193a8240 100644
--- a/drivers/net/ethernet/mscc/ocelot.c
+++ b/drivers/net/ethernet/mscc/ocelot.c
@@ -2230,9 +2230,18 @@ void ocelot_set_cpu_port(struct ocelot *ocelot, int cpu,
* Only one port can be an NPI at the same time.
*/
if (cpu < ocelot->num_phys_ports) {
+ int mtu = VLAN_ETH_FRAME_LEN + OCELOT_TAG_LEN;
+
ocelot_write(ocelot, QSYS_EXT_CPU_CFG_EXT_CPUQ_MSK_M |
QSYS_EXT_CPU_CFG_EXT_CPU_PORT(cpu),
QSYS_EXT_CPU_CFG);
+
+ if (injection == OCELOT_TAG_PREFIX_SHORT)
+ mtu += OCELOT_SHORT_PREFIX_LEN;
+ else if (injection == OCELOT_TAG_PREFIX_LONG)
+ mtu += OCELOT_LONG_PREFIX_LEN;
+
+ ocelot_port_set_mtu(ocelot, cpu, mtu);
}
/* CPU port Injection/Extraction configuration */