What's the difference between CONFIG_R8169 and CONFIG_R8169_VLAN?

Question

.config from /usr/src/linux-2.6.38.8 contains:

CONFIG_R8169=m
CONFIG_R8169_VLAN=y

What's the difference between CONFIG_R8169 and CONFIG_R8169_VLAN?

Answer 1

CONFIG_R8169_VLAN enables support for the VLAN/802.1Q code in the r8169 driver. For an introduction in VLANs see http://en.wikipedia.org/wiki/IEEE_802.1Q

A small tip for the future, if you need to determine what a specific config option in the kernel does you should have a look at the integrated help text, e.g: help text for R8169_VLAN. Sometimes it also helps to look at the driver itself and check what the config option does.