mlxsw: Adjust MTU value to hardware check

Browse source

Ethernet frame consists of - Ethernet header, payload, FCS. The MTU value
which is used by user is the size of the payload, which means that when
user sets MTU to X, the total frame size will be larger due to the addition
of the Ethernet header and FCS.

Spectrum ASICs take into account Ethernet header and FCS as part of packet
size for MTU check. Adjust MTU value when user sets MTU, to configure the
MTU size which is required by hardware. The Tx header length which was used
by the driver is not relevant for such calculation, take into account
Ethernet header (with VLAN extension) and FCS.

Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Link: https://lore.kernel.org/r/f3203c2477bb8ed18b1e79642fa3e3713e1e55bb.1718275854.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

...

This commit is contained in:

Amit Cohen 2024-06-13 16:07:55 +02:00 • committed by Jakub Kicinski

parent cae7fd47df

commit d361536fc2

2 changed files with 2 additions and 1 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

1

drivers/net/ethernet/mellanox/mlxsw/port.h

View file

2

drivers/net/ethernet/mellanox/mlxsw/spectrum.c

View file