On 2013-01-15 11:20 AM, Krishna Chaitanya wrote: > Hi Johannes, > > Is there any work in progress/planned related to Tx AMSDU logic in mac80211? > Even though only Rx is mandatory, but to test the Rx we need the Tx. > > I see that the support is there in mwifiex(marvell's) driver. So is > there any patent/legal issue before we can implement one? The issue with AMSDU Tx is a technical one, not a legal one: A-MSDU aggregation needs a queue and some buffering to properly work, A-MPDU needs the same. A-MPDU is typically implemented in the driver/firmware. Doing extra buffering/queueing in mac80211 is not a good idea, as it would add significant extra latency in the Tx path, so A-MSDU aggregation really needs to be done on the same queue. For implementing A-MSDU in ath9k, my plan is to share the per-sta-tid A-MPDU driver queues between mac80211 and ath9k. That way I can keep the logic inside mac80211 with no added buffering/latency. I might even be able to have an A-MSDU aggregation fastpath that happens before 802.11 header encapsulation. The problem with this approach is that it doesn't work with drivers using hardware/firmware based A-MPDU aggregation. Such drivers will probably either have to do A-MSDU in firmware as well, or - Felix -- 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
