[PATCH 1/2] wifi: mac80211: introduce ieee80211_refresh_tx_agg_session_timer()

[Ryder Lee]

On Fri, 2023-02-17 at 19:01 +0100, Johannes Berg wrote:
> On Sat, 2023-02-18 at 01:50 +0800, Ryder Lee wrote:
> > This allows low level drivers to refresh the tx agg session timer,
> > based on
> > querying stats from the firmware usually. Especially for some mt76
> > devices
> > support .net_fill_forward_path would bypass mac80211, which leads
> > to tx BA
> > session timeout for certain clients.
> > 
> 
> Does it even matter? We could just request sessions without a timeout
> in
> the first place.
> 

I think we're already. Our main issue is performance periodically drops
every few seconds when .net_fill_forward_path is enabled. Wireless
client have normal 500+ Mb/s iperf3 download speed for several seconds.
Then it drops less than 100 Mb/s for several seconds. Then everything
repeats. Issue occurs only on certain clients. (i.e. Intel cards AX200,
AX1675, Advanced-N 6235 in Win11)

> Or do you have a strong reason to need the timeout, such as limited
> hardware resources for (TX) aggregation sessions?
> 
> But then maybe you should just time them out based on FW statistics
> directly, rather than having to periodically refresh the timer in
> mac80211?
> 
> I don't mind the patch, and I'll happily take it if it's needed, I'm
> just wondering if that isn't a very roundabout way of achieving
> things.
> 
> johannes