| Message ID | 20210524213313.1437891-3-andrew@lunn.ch (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | MTU fixes for mv88e6xxx | expand |
| Context | Check | Description |
|---|---|---|
| netdev/cover_letter | success | Link |
| netdev/fixes_present | success | Link |
| netdev/patch_count | success | Link |
| netdev/tree_selection | success | Clearly marked for net |
| netdev/subject_prefix | success | Link |
| netdev/cc_maintainers | fail | 1 blamed authors not CCed: chris.packham@alliedtelesis.co.nz; 3 maintainers not CCed: olteanv@gmail.com chris.packham@alliedtelesis.co.nz vivien.didelot@gmail.com |
| netdev/source_inline | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Link |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/build_32bit | success | Errors and warnings before: 0 this patch: 0 |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/verify_fixes | success | Link |
| netdev/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 39 lines checked |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 0 this patch: 0 |
| netdev/header_inline | success | Link |
On Mon, May 24, 2021 at 11:33:12PM +0200, Andrew Lunn wrote: > The MTU passed to the DSA driver is the payload size, typically 1500. > However, the switch uses the frame size when applying restrictions. > Adjust the MTU with the size of the Ethernet header and the frame > checksum. > > Fixes: 1baf0fac10fb ("net: dsa: mv88e6xxx: Use chip-wide max frame size for MTU") > Reported by: 曹煜 <cao88yu@gmail.com> > Signed-off-by: Andrew Lunn <andrew@lunn.ch> > --- > drivers/net/dsa/mv88e6xxx/chip.c | 12 ++++++------ > drivers/net/dsa/mv88e6xxx/port.c | 2 ++ > 2 files changed, 8 insertions(+), 6 deletions(-) > > diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c > index cbedaee3cefd..593dc734582e 100644 > --- a/drivers/net/dsa/mv88e6xxx/chip.c > +++ b/drivers/net/dsa/mv88e6xxx/chip.c > @@ -2775,8 +2775,8 @@ static int mv88e6xxx_setup_port(struct mv88e6xxx_chip *chip, int port) > if (err) > return err; > > - /* Port Control 2: don't force a good FCS, set the maximum frame size to > - * 10240 bytes, disable 802.1q tags checking, don't discard tagged or > + /* Port Control 2: don't force a good FCS, set the MTU size to > + * 10222 bytes, disable 802.1q tags checking, don't discard tagged or > * untagged frames on this port, do a destination address lookup on all > * received packets as usual, disable ARP mirroring and don't send a > * copy of all transmitted/received frames on this port to the CPU. > @@ -2795,7 +2795,7 @@ static int mv88e6xxx_setup_port(struct mv88e6xxx_chip *chip, int port) > return err; > > if (chip->info->ops->port_set_jumbo_size) { > - err = chip->info->ops->port_set_jumbo_size(chip, port, 10240); > + err = chip->info->ops->port_set_jumbo_size(chip, port, 10222); > if (err) > return err; > } > @@ -2885,10 +2885,10 @@ static int mv88e6xxx_get_max_mtu(struct dsa_switch *ds, int port) > struct mv88e6xxx_chip *chip = ds->priv; > > if (chip->info->ops->port_set_jumbo_size) > - return 10240; > + return 10240 - ETH_HLEN - ETH_FCS_LEN; > else if (chip->info->ops->set_max_frame_size) > - return 1632; > - return 1522; > + return 1632 - ETH_HLEN - ETH_FCS_LEN; > + return 1522 - ETH_HLEN - ETH_FCS_LEN; > } > > static int mv88e6xxx_change_mtu(struct dsa_switch *ds, int port, int new_mtu) > diff --git a/drivers/net/dsa/mv88e6xxx/port.c b/drivers/net/dsa/mv88e6xxx/port.c > index f77e2ee64a60..28664ea91244 100644 > --- a/drivers/net/dsa/mv88e6xxx/port.c > +++ b/drivers/net/dsa/mv88e6xxx/port.c > @@ -1277,6 +1277,8 @@ int mv88e6165_port_set_jumbo_size(struct mv88e6xxx_chip *chip, int port, > u16 reg; > int err; > > + size += ETH_HLEN + ETH_FCS_LEN; > + > err = mv88e6xxx_port_read(chip, port, MV88E6XXX_PORT_CTL2, ®); > if (err) > return err; > -- > 2.31.1 > Does the hardware account for VLAN-tagged frames automatically? If not, it is not uncommon to use VLAN_ETH_HLEN instead of ETH_HLEN (the VLAN header is not part of the L2 SDU).
diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c index cbedaee3cefd..593dc734582e 100644 --- a/drivers/net/dsa/mv88e6xxx/chip.c +++ b/drivers/net/dsa/mv88e6xxx/chip.c @@ -2775,8 +2775,8 @@ static int mv88e6xxx_setup_port(struct mv88e6xxx_chip *chip, int port) if (err) return err; - /* Port Control 2: don't force a good FCS, set the maximum frame size to - * 10240 bytes, disable 802.1q tags checking, don't discard tagged or + /* Port Control 2: don't force a good FCS, set the MTU size to + * 10222 bytes, disable 802.1q tags checking, don't discard tagged or * untagged frames on this port, do a destination address lookup on all * received packets as usual, disable ARP mirroring and don't send a * copy of all transmitted/received frames on this port to the CPU. @@ -2795,7 +2795,7 @@ static int mv88e6xxx_setup_port(struct mv88e6xxx_chip *chip, int port) return err; if (chip->info->ops->port_set_jumbo_size) { - err = chip->info->ops->port_set_jumbo_size(chip, port, 10240); + err = chip->info->ops->port_set_jumbo_size(chip, port, 10222); if (err) return err; } @@ -2885,10 +2885,10 @@ static int mv88e6xxx_get_max_mtu(struct dsa_switch *ds, int port) struct mv88e6xxx_chip *chip = ds->priv; if (chip->info->ops->port_set_jumbo_size) - return 10240; + return 10240 - ETH_HLEN - ETH_FCS_LEN; else if (chip->info->ops->set_max_frame_size) - return 1632; - return 1522; + return 1632 - ETH_HLEN - ETH_FCS_LEN; + return 1522 - ETH_HLEN - ETH_FCS_LEN; } static int mv88e6xxx_change_mtu(struct dsa_switch *ds, int port, int new_mtu) diff --git a/drivers/net/dsa/mv88e6xxx/port.c b/drivers/net/dsa/mv88e6xxx/port.c index f77e2ee64a60..28664ea91244 100644 --- a/drivers/net/dsa/mv88e6xxx/port.c +++ b/drivers/net/dsa/mv88e6xxx/port.c @@ -1277,6 +1277,8 @@ int mv88e6165_port_set_jumbo_size(struct mv88e6xxx_chip *chip, int port, u16 reg; int err; + size += ETH_HLEN + ETH_FCS_LEN; + err = mv88e6xxx_port_read(chip, port, MV88E6XXX_PORT_CTL2, ®); if (err) return err;
The MTU passed to the DSA driver is the payload size, typically 1500. However, the switch uses the frame size when applying restrictions. Adjust the MTU with the size of the Ethernet header and the frame checksum. Fixes: 1baf0fac10fb ("net: dsa: mv88e6xxx: Use chip-wide max frame size for MTU") Reported by: 曹煜 <cao88yu@gmail.com> Signed-off-by: Andrew Lunn <andrew@lunn.ch> --- drivers/net/dsa/mv88e6xxx/chip.c | 12 ++++++------ drivers/net/dsa/mv88e6xxx/port.c | 2 ++ 2 files changed, 8 insertions(+), 6 deletions(-)