| From b2f7c18c351737c2a053c39c09ef50870fd78c06 Mon Sep 17 00:00:00 2001 |
| From: Vladimir Oltean <vladimir.oltean@nxp.com> |
| Date: Thu, 14 Nov 2019 17:03:25 +0200 |
| Subject: [PATCH] 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> |
| --- |
| drivers/net/ethernet/mscc/ocelot.c | 9 +++++++++ |
| drivers/net/ethernet/mscc/ocelot.h | 2 ++ |
| 2 files changed, 11 insertions(+) |
| |
| --- a/drivers/net/ethernet/mscc/ocelot.c |
| +++ b/drivers/net/ethernet/mscc/ocelot.c |
| @@ -2229,9 +2229,18 @@ void ocelot_set_cpu_port(struct ocelot * |
| * 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 */ |
| --- a/drivers/net/ethernet/mscc/ocelot.h |
| +++ b/drivers/net/ethernet/mscc/ocelot.h |
| @@ -65,6 +65,8 @@ struct frame_info { |
| #define IFH_REW_OP_ORIGIN_PTP 0x5 |
| |
| #define OCELOT_TAG_LEN 16 |
| +#define OCELOT_SHORT_PREFIX_LEN 4 |
| +#define OCELOT_LONG_PREFIX_LEN 16 |
| |
| #define OCELOT_SPEED_2500 0 |
| #define OCELOT_SPEED_1000 1 |