On 9/27/2023 3:12 PM, Linus Walleij wrote:

As we don't specify the MTU in the driver, the framework
will fall back to 1500 bytes and this doesn't work very
well when we try to attach a DSA switch:

  eth1: mtu greater than device maximum
  ixp4xx_eth c800a000.ethernet eth1: error -22 setting
  MTU to 1504 to include DSA overhead

After locating an out-of-tree patch in OpenWrt I found
suitable code to set the MTU on the interface and ported
it and updated it. Now the MTU gets set properly.

Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Linus Walleij <redacted>
---
Changes in v3:
- Fix some coding style and initialization style.
- Collect Jacob's review tag.
- Link to v2: https://lore.kernel.org/r/20230925-ixp4xx-eth-mtu-v2-1-393caab75cb0@linaro.org (local)

Thanks for the cleanups! Looks good to me still.

-Jake