| Message ID | 20240717090820.894234-2-martin@strongswan.org (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 66b6095c264e1b4e0a441c6329861806504e06c6 |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | net: dsa: Fix chip-wide frame size config in some drivers | expand |
On Wed, Jul 17, 2024 at 11:08:19AM +0200, Martin Willi wrote: > Marvell chips not supporting per-port jumbo frame size configurations use > a chip-wide frame size configuration. In the commit referenced with the > Fixes tag, the setting is applied just for the last port changing its MTU. > > While configuring CPU ports accounts for tagger overhead, user ports do > not. When setting the MTU for a user port, the chip-wide setting is > reduced to not include the tagger overhead, resulting in an potentially > insufficient maximum frame size for the CPU port. Specifically, sending > full-size frames from the CPU port on a MV88E6097 having a user port MTU > of 1500 bytes results in dropped frames. > > As, by design, the CPU port MTU is adjusted for any user port change, > apply the chip-wide setting only for CPU ports. > > Fixes: 1baf0fac10fb ("net: dsa: mv88e6xxx: Use chip-wide max frame size for MTU") > Suggested-by: Vladimir Oltean <olteanv@gmail.com> > Signed-off-by: Martin Willi <martin@strongswan.org> > --- Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c index 07c897b13de1..5b4e2ce5470d 100644 --- a/drivers/net/dsa/mv88e6xxx/chip.c +++ b/drivers/net/dsa/mv88e6xxx/chip.c @@ -3626,7 +3626,8 @@ static int mv88e6xxx_change_mtu(struct dsa_switch *ds, int port, int new_mtu) mv88e6xxx_reg_lock(chip); if (chip->info->ops->port_set_jumbo_size) ret = chip->info->ops->port_set_jumbo_size(chip, port, new_mtu); - else if (chip->info->ops->set_max_frame_size) + else if (chip->info->ops->set_max_frame_size && + dsa_is_cpu_port(ds, port)) ret = chip->info->ops->set_max_frame_size(chip, new_mtu); mv88e6xxx_reg_unlock(chip);
Marvell chips not supporting per-port jumbo frame size configurations use a chip-wide frame size configuration. In the commit referenced with the Fixes tag, the setting is applied just for the last port changing its MTU. While configuring CPU ports accounts for tagger overhead, user ports do not. When setting the MTU for a user port, the chip-wide setting is reduced to not include the tagger overhead, resulting in an potentially insufficient maximum frame size for the CPU port. Specifically, sending full-size frames from the CPU port on a MV88E6097 having a user port MTU of 1500 bytes results in dropped frames. As, by design, the CPU port MTU is adjusted for any user port change, apply the chip-wide setting only for CPU ports. Fixes: 1baf0fac10fb ("net: dsa: mv88e6xxx: Use chip-wide max frame size for MTU") Suggested-by: Vladimir Oltean <olteanv@gmail.com> Signed-off-by: Martin Willi <martin@strongswan.org> --- drivers/net/dsa/mv88e6xxx/chip.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)