Really free Atheros driver for Linux
Posted Nov 15, 2006 18:33 UTC (Wed) by proski
In reply to: Really free Atheros driver for Linux
Parent article: SFLC: OpenBSD Atheros driver is clean
I think the Devicescape note should be a separate story.
Basically, the job of a wireless driver should be to send and receive 802.11 packets. Presenting this to the userspace should be done by the 802.11 stack.
The networking in Linux is implemented through network devices. A single network device is typically one physical device connected to one subnet on one medium with one packet queue. Note the inherent overload of functions - the same interface represents hardware, a subnet, a medium and a network queue.
An advanced 802.11 device can act as one physical device on one medium (radio channel) with multiple subnets (virtual APs and WDS connections). The packet queue is common on the physical, but users may want to regulate it on the subnet level as well.
The question is basically how we want to map this to the traditional network device paradigm. I understand that d80211 associates the physical device and the network queue to the master interface and the medium to the "wiphy", whatever it is.
It's desirable to have one interface representing the common part of the wireless device. If we move everything to wiphy, we lose control over the queue because it's done on the network interface level. If we move everything to the master device, we won't lose anything. However, Johannes seems to dislike having a network interface without the ability to send or receive packets. Unfortunately, the alternative is a major surgery of the networking to decouple queue management from the network devices.
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