To do qos properly there needs to be a single net_device that a single qdisc can be installed on - this alone is a good reason for a master net_device. (there must be a single 802.11 qdisc for a single physical piece of hardware). Here is another reason (for hardware devices that do not include a MLME in hardware):
In the Devicescape stack the hardware driver (called the low level driver) uses an internal interface to the rest of the stack. The master net_device is created by the rest of the stack (80211.o module). I would like to change this, so that the hardware driver itself creates a net_device, with an 802.11 ARP_HDR. This would be the master device, and the interface between the kernel 802.11 code and a hardware 802.11 device that does not implement the MLME in hardware. The 80211.o module in the kernel would hook itself into this device by watching for the broadcast message when a new device is registered, and automatically installing the 802.11 qdisc on the new device. When the hadware receives 802.11 frames the hardware device driver would set the protocol type to 802.11 before calling netif_rx, and the 80211.o module would register itself as a protocol handler for 802.11. This change would remove the current special internal interface in the Devicescape stack between the hardware driver and the core of the stack - and would make the stack better integrated with the kernel. The design here is similar to the VLAN code for the RX direction, but using the qdisc for both queueing and part of the stack implementation is a new direction for the TX. Simon -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jiri Benc Sent: Tuesday, January 17, 2006 2:05 AM To: Jouni Malinen Cc: Krzysztof Halasa; Mike Kershaw; netdev@vger.kernel.org; Stefan Rompf; John W.Linville Subject: Re: State of the Union: Wireless On Mon, 16 Jan 2006 19:07:51 -0800, Jouni Malinen wrote: > Actually, there is a use for the master device. It can be used to > monitor what is going on over the radio from all virtual APs/STAs, > e.g., by running Ethereal on it. You can add a new "soft" monitor interface and use it instead. There is no need for separate master device. -- Jiri Benc SUSE Labs - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
