Linux Kernel Ethernet
This page documents Ethernet drivers on the Linux kernel. Typically Ethernet drivers are documented through the Documentation/ section of the kernel. This page is for those drivers that choose to document themselves through a wiki rather than plain text ASCII files. This follows the tradition of documentation followed by the wireless subsystem .
Here is the list of our wiki-documented Ethernet drivers. alx - Qualcomm Atheros (QCA) Ethernet driver.
- alx  - Qualcomm Atheros (QCA) Ethernet driver - submission coming soon
Ethernet hardware specifications
We have section dedicated to Ethernet hardware specifications 
In-kernel Ethernet documentation
Some Ethernet drivers are documented under the Documentation/networking/ directory of the Linux kernel. You can also refer to that for vendor who wish to document their drivers there.