Re: [PATCH 1/3] mac80211: Include sequence number in IBSS and Mesh beacons

[Ivo van Doorn <ivdoorn@gmail.com>]

On Wednesday 09 July 2008, Johannes Berg wrote:
> 
> > If rt2x00 would use a global lock to block all TX and beacons, then yes.
> > But rt2x00 uses per-queue locking. When a beacon is being updated rt2x00
> > will still allow regular frames to be queued.
> 
> That just widens the window. And if you have multiple queues then you
> can't do sw sequence numbers anyway because the hardware might reorder
> the frames.

That doesn't seem to be a problem in the legacy drivers, so I guess the hardware
does *something* to prevent problems.

> > As far as rt2x00 is concerned, all hardware that supports multi-bss also
> > support HW sequence counters. rt2400pci and rt2500pci are the only ones
> > requiring SW sequence counters, and they can't do multi-bss.
> 
> Do they keep per-BSS counters?

Not sure what you mean, but rt2400pci and rt2500pci don't support multi-bss,
so they wouldn't have per-BSS counters.
rt61pci and rt73usb do support multi-bss and keep the sequence counting
completely in firmware/hardware and I am not sure how they can be read
by the driver. So I don't know how those are stored either.


Ivo