Is iwlwifi or iwldvm or wext the wireless driver?

Question

From https://wireless.wiki.kernel.org/en/users/Drivers/iwlwifi:

iwlwifi is the wireless driver for Intel's current wireless chips.

From https://wireless.wiki.kernel.org/en/users/Drivers/iwlwifi#firmware

Device  Kernels     Module  Firmware
Intel® Wireless WiFi 5150AGN    2.6.29+     iwldvm  iwlwifi-5150-ucode-8.24.2.2.tgz

which says iwldvm is the "module".

1. Isn't a driver a module?

2. which is the wireless driver (module) for the wifi adapter, iwlwifi or iwldvm?

3. Is wext also some kind of driver module, but why is it not listed in lsmod or lshw? See also https://unix.stackexchange.com/a/198509/674

Thanks.

Answer 1

Not every module is a driver, and drivers can use multiple modules. For further information read this U&L thread.

As for your specific question:

$ modinfo iwlwifi | grep description
description:    Intel(R) Wireless WiFi driver for Linux
$ modinfo iwldvm | grep description
description:    Intel(R) Wireless WiFi Link AGN driver for Linux
$ modinfo iwldvm | grep depends
depends:        iwlwifi,mac80211,cfg80211

As you see, the iwldvm module belongs to a driver for a very specific group of Intel WiFi chips. It is optimized to work the best with the WiFi Link AGN devices.

However, it says to depend on iwlwifi, which, on the contrary, simply states to be a "Intel WiFi driver", so it is a generic driver, which should work with a lot of Intel WiFi devices.

I don't know the exact way Intel drivers work, but I could imagine the following:

iwlwifi enables basic interaction with the WiFi device. If you only had iwlwifi, your WiFi could work perfectly, reduced or not at all.

For the latter two cases, here comes a more specified module, such as iwldvm, which contains operations needed for more complex tasks. With this driver, the WiFi should work properly, but it still requires iwlwifi.