[PATCH 5/8] usb: eth: Add CDC ECM support

[Jonas Karlman]

Hi Marek,

On 7/11/2026 9:57 PM, Marek Vasut wrote:
> On 7/11/26 6:08 PM, Jonas Karlman wrote:
>> Add support for CDC ECM (Communications Device Class, Ethernet Control
>> Model) devices.
>>
>> References:
>> - [USBECM12] USB Subclass Specification for Ethernet Control Model 1.2.
>> - [USBCDC12] USB Class Definitions for Communications Devices 1.2.
>> - [USB20] USB Specification 2.0.
>>
>> Signed-off-by: Jonas Karlman <jonas at kwiboo.se>
> Is this pulled from Linux or is this written from scratch ?

As stated in the cover letter this driver was written from scratch.

  The driver implementations was created based of the CDC ECM 1.2 and
  CDC NCM 1.1 specifications and was tested on a few different USB
  Ethernet adapters using ASIX or Realtek IC.
At some point I looked and compared to Linux to ensure ordering of e.g.
control messages and size limitations where closely matched.

In more detail the NCM driver was first created and tested on AX88179.
Later when tested on RTL815x there were some issues, so I also added the
ECM variant and tested that on both AX88179 and RTL815x.

The ECM variant is likely enough for U-Boot purposes, however NCM still 
has some good features such as custom MAC-addresses. So, I included both
in this series, with NCM being preferred over ECM due to driver list
sorting.

Regards,
Jonas