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

[Felix Fietkau <nbd@openwrt.org>]

On 2010-06-28 12:20 PM, Björn Smedman wrote:
> 2010/6/28 Felix Fietkau <nbd@openwrt.org>:
>> On 2010-06-28 2:01 AM, Björn Smedman wrote:
> [snip]
>>> I guess the real solution is your rewrite... But in the mean time
>>> perhaps we can memcpy the tx_info control from the last subframe to
>>> the first before calling ath_buf_set_rate() in ath_tx_sched_aggr()?
>>> Could that have any side effects? It could make the aggregate size go
>>> over the 4 ms limit I guess... How bad is that?
>> There's an easy solution which would take into account the 4ms frame
>> limit properly, and which could work without any memcpy() hacks:
>>
>> I could just grab a pointer to the last buffer in the tid queue in the
>> ath_tx_sched_aggr() function, then pass it to ath_lookup_rate() via
>> ath_tx_form_aggr(), and also to ath_buf_set_rate(). Then I make those
>> functions use this last buffer as reference for the rate lookup.
> 
> Sounds better to use the rate control from the last buffer in the tid
> queue. But be careful if you don't memcpy it to the first frame of the
> aggregate then the feedback calculated in ath_tx_rc_status() after tx
> will be incorrect again, no?
Right. I intend to let ath_buf_set_rate() set the rates array of the
first subframe accordingly.

- Felix