Stefan Sperling <s...@stsp.name> wrote: > This patch attempts to add support for receiving A-MSDUs to iwm(4). > If you are using iwm(4) then please run with this patch and let me > know if it causes regressions. Thanks! > > ACHTUNG: This patch breaks iwx(4)! Don't use it there! For this reason, > the patch can neither be committed nor be put into snapshots!!! > > Our net80211 stack de-aggregates A-MSDUs in software. This works fine with > iwm 7k and 8k devices. However, iwm 9k devices de-aggregate A-MSDUs in > hardware and net80211 is currently unable to handle this. > > Our current iwm 9k code only works because long ago I disabled reception > of A-MSDUs for all devices. Unfortunately, the only way to get A-MSDUs > working on 9k hardware is to add a bunch of driver-specific code which > handles de-aggregation. Otherwise, net80211 will drop frames which appear > to arrive out of order, or appear as duplicates even though they were > simply part of the same A-MSDU and thus share a sequence number. > The driver can re-order frames correctly based on information provided > by firmware. I'd rather implement this than letting these devices miss > out on A-MSDUs because the Rx speed advantage can be significant, around > 80/90 Mbps (but this will very much depend on the AP). > > If these A-* acronyms don't make sense and you'd like to know more, here > is a fairly good explanation: https://mrncciew.com/2013/04/11/a-mpdu-a-msdu/ > Note that we care about the nested case, which is also mentioned in this > article but not explained in detail. It's simply an A-MSDU stashed inside > an A-MPDU. If an AP can do 11AC, then it should support this. > > iwx(4) hardware has the same problem. > If this patch works fine on iwm(4) then I can port the changes to iwx(4), > do another round of testing, and eventually commit to both drivers at > the same time. > > Some of the changes below are based on code from the Linux iwlwifi driver. > I am not entirely happy with some of its style. But the code should be in > good enough shape to be tested.
No regression noticed here for several days under my normal workload. iwm0 at pci2 dev 0 function 0 "Intel Dual Band Wireless AC 7265" rev 0x59, msi iwm0: hw rev 0x210, fw ver 17.3216344376.0, address dc:53:60:4a:b1:ea Tim.
