Re: [RFC v2] minstrel_ht: new rate control module for 802.11n

[Felix Fietkau <nbd@openwrt.org>]

On 2010-03-07 6:59 PM, Christian Lamparter wrote:
> On Sunday 07 March 2010 17:39:47 Felix Fietkau wrote:
>> here is an updated version of my minstrel_ht code. Since the last
>> version, I've added the following improvements:
>> 
>> - Use accurate A-MPDU statistics from tx feedback
>> - Rewrite the sampling algorithm to optimize for good A-MPDU lengths
>>   and faster throughput recovery
>> - Implement .rate_update to handle changes in HT capabilities or 
>>   channel bandwidth
>> - Remove the private tx flags hack
>> 
>> With the new version, performance has improved visibly for HT40 in all
>> of my tests. I think it's getting closer to being ready for inclusion.
>> ---
> Just released carl9170 1.0.3.1 which now uses minstrel_ht.
> 
> I found a few things, not sure if they are bugs in the driver
> or minstrel_ht code. (Patch attached, but added the comments
> as a response to the code) 
Thanks. How well does it perform in your tests compared to the old rc?

> on startup, carl9170 complains about non-aggregated
> (CTL_AMPDU not set) MCS frames. I had to add an
> alternative path for these _early_ frames. They are
> now send with the "lowest" legacy rate and aren't
> rejected by the driver/HW.
Why does it complain - is that a driver thing or does the hardware
really refuse it? I didn't see anything in the standard that mandates
the use of A-MPDU with MCS rates.

- Felix