@david,
just curious, did you try the simple test with the un-modified driver and then test it with the modified driver you just put up and see the difference? It may only affect 1200/1900 models because the 3200 implements amsdu differently.
To all
In case you haven't been following the thread, and especially if you have complained or noticed laggyness or bad lag or ping, especially when playing multiplayer games when using wifi (2.4GHz and 5.0GHz), which is when the problem is most noticeable (see posts on page 111 towards the top for a recent complaints), please read the following.
The problem is that if your router (both 2.4 and 5GHz), when doing basically any broadband significant activity, such as watching youtube, downloading a file, or simply browsing a webpage, activates something know as amsdu. I believe it is some sort of a caching mechanism. However it doesn't work properly and causes an increase of ping of over 30ms and packet loss when doing anything over wireless. Just FYI, this is not related to buffer-bloat in any way at all.
A good test is this: Start pinging your router continuous from your PC, observe the pings (which should be normal, 1 - 3 ms, no packet loss) for a few seconds, then simply refresh a webpage, load a youtube video, do basically anything that uses bandwidth. You'll see your pings to 192.168.1.1 (the router) jump to 30+ ms when actually using it, and that there is occasional packet loss as well. Stop all broadband activity and the pings will go back to normal. Pings don't activate amsdu which is why we can do this test which is extremely quick and easy.
So the consequence is this: the ping when playing a multiplayer game (for example) instead of just being X ms to the gaming server is actually X + Y ms where Y is the usually negligible 1ms ping to the router. But because of the bug in amsdu, Y (the wireless connection between your computer and the router) becomes approx. 30 ms. Assuming X is 40ms, then instead of the ping to your game server being 41 ms (which is indistinguishable from 40 ms), it is now 70 ms! And remember that packet loss is also introduced causing more lag.
In most other uses (except for VoIP and live video streaming services and other similar software), the increased ping is not noticed because if the ping to a website is 100ms, with the amsdu problem, it is now approx 130ms, but not a large enough increase to notice. Now take VoIP into account, and the increased ping combined with packet losses can make the connection horrible.
So the solution is clear, until amsdu is properly fixed (which won't happen for a long, long time would be my guess, because I think this problem only affects the 1200/1900 models, and all work going into the driver currently is for the 3200), the best solution is simply to disable it, which is what the driver @david just uploaded does. There are no ill-effects or issues introduced with it being disabled (such as loss of speed, difficulty in connecting, etc)
So please, do yourself a favor and install the updated kmod-mwlwifi .ipk driver file that @david posted and test it out with amsdu disabled. You can easily use the ping test I mentioned above to clearly see the difference.
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