On Thursday 18 September 2008, Tomas Winkler wrote: > On Tue, Sep 16, 2008 at 9:05 PM, Ivo van Doorn <ivdoorn@xxxxxxxxx> wrote: > > Hi, > > > >> We're considering redesigning how aggregation works on mac80211 to > >> ensure its vendor neutral and to remove as much as redundant code in > >> drivers. We'd like some feedback from people and driver developers, > >> even those who haven't *yet* posted their new shiny 11n drivers, like > >> Marvell or Ralink driver developers. > > > > Well technically speaking there are 2 Ralink drivers in the Kernel already > > which *should* support aggregation (rt61 and rt73). > > > > I'm sorry I have not read the entire thread on the new aggregation support > > yet, but I'll write what I know from rt61/rt73/rt2800 here anyway. :) > > > >> Ivo, are you familiar yet with how aggregation works on Ralink > >> hardware? Does the new 11n hardware require firmware? Specifically > >> we're curious about how the hardware queues are managed. > > > > Ralink defines 4 queues, 1 Management queue (can be abused as regular TX queue) > > and a Beacon queue. > > > > There is no such thing as seperate aggregation queues, as soon as the device > > wants to perform aggregation it grabs a normal entry from the TX queue, > > and assignes all frames to it. > > > > rt61: 5 addresses can be provided for Aggrated frames, I am not sure > > if the first is a header only frame or not. > > rt73: Not sure what should be done > > rt2800: 2 addresses can be provided, where the first is a header/descriptor > > only address. In the second address frames can be provided. > > > Because the aggregated frame is created directly into a TX entry, no other > > frames should go through that queue until the aggregated frame has been > > completed. > > > > What type of aggregation is this? AMSDU or AMPDU? In AMPDU you need > somehow handle > out of order resend of the packets. rt61 and rt2800 looks more like > AMSDU (Not sure) we don't support that in iwlwifi TX side of it yet, > it just doesn't outperform AMPDU aggregation. > Tomas It is a bit confusing since comments, variable names are a conflicting eachother in the legacy driver code. Comments state MSDU where variables are named MPDU and later the same variable is accompanies with comments regarding MPDU. I really have to look deeper in the actual implementation to see what the driver is doing exactly before I can answer the question what aggregation it is using. > > I'm afraid that is currently all the information I got at this time, > > It is only a little, but I never got around to fully look into the aggregation support, > > although I definately want it implemented in the drivers to increase the > > performance a bit. :) > > Need to find out what kind of aggregation the cards support. For TX > AMSDU we need add more code into mac80211, the AMSDU sub frames have > 14 bytes (eth) headers. Ivo -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
