Re: ATH9K software retry

[Felix Fietkau <nbd@openwrt.org>]

On 2014-02-06 14:06, Cedric VONCKEN wrote:
> In xmit.c the function ath_tx_complete_aggr test if the fi->retries <
> ATH_MAX_SW_RETRIES.
> 
> If this condition is true, ATH9K handle software retry. 
> 
> Minstrel set in the frame one or more rates, for each rate minstrel set
> a retries count. I think is sufficient.
> 
> Why ATH9K need to manage the software retries?
The retries configured for minstrel_ht are used for hardware retries of
single frames and full A-MPDU transmissions. Software retries are used
for individual subframes that are sent as part of A-MPDUs.
This is required, because failed subframes are frequent with higher MCS
rates and A-MPDU.

> With the test we have a minimal of 30 retries (ATH_MAX_SW_RETRIES is set
> to 30).
> 
> I plan to remove the software retry int ATH9K, before I would like to
> know if theses retries is necessary.
Removing software retry functionality is a very bad idea.

- Felix