Hi Russell,

On Tue, May 23, 2023 at 04:29:10PM +0200, Lukasz Majewski wrote:

quoted

Switches from mv88e6250 family (the marketing name - "Link Street",
including mv88e6020 and mv88e6071) need the possibility to setup the
maximal frame size, as they support frames up to 2048 bytes.

Signed-off-by: Lukasz Majewski <lukma@denx.de>  

Adding this function doesn't allow the "possibility" for a larger
frame size. Adding it changes the value returned from
mv88e6xxx_get_max_mtu() to be a larger frame size, so all switches
that make use of mv88e6250_ops will be expected to support this
larger frame size. Do we know whether that is true?

According to functional specification - the 6070, 6071, 6250, 6020 and
6220 have "Max Frame Size" of 2048 bytes.

The mv88e6xxx_get_max_mtu() now will:
return 1632 - VLAN_ETH_HLEN - EDSA_HLEN - ETH_FCS_LEN;

which is acceptable and safe for this family of chips.

There were patches floating about a while ago that specified the
maximum size in struct mv88e6xxx_info, but it seems those died a
death.

Those patches seems to not be strictly required after Vladimir's work.

The v7 provides what I need, so yes - extra patches from v6 can be
discarded.


Best regards,

Lukasz Majewski

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