[PATCH] mac80211: check ATF flag in ieee80211_next_txq()

[Ryder Lee]

On Wed, 2021-01-06 at 16:41 +0100, Toke Høiland-Jørgensen wrote:
> Felix Fietkau <nbd at nbd.name> writes:
> 
> > On 2021-01-06 11:51, Toke Høiland-Jørgensen wrote:
> >> Ryder Lee <ryder.lee at mediatek.com> writes:
> >> 
> >>> The selected txq should be scheduled unconditionally if
> >>> NL80211_EXT_FEATURE_AIRTIME_FAIRNESS is not set by driver.
> >>>
> >>> Also put the sta to the end of the active_txqs list if
> >>> deficit is negative then move on to the next txq.
> >> 
> >> Why is this needed? If the feature is not set, no airtime should ever be
> >> accounted to the station, and so sta->airtime[txqi->txq.ac].deficit will
> >> always be 0 - so you're just adding another check that doesn't actually
> >> change the behaviour, aren't you?
> >
> > I think it might make sense to keep airtime reporting even when airtime
> > fairness is disabled at run time, so this patch makes sense to me.
> > Instead of this patch, the right place to deal with this would probably
> > be ieee80211_sta_register_airtime.
> 
> When the fairness mechanism is user-disabled I agree it makes sense to
> still keep the accounting; and in fact that's what
> ieee80211_sta_register_airtime() already does when the accounting is
> turned off by way of the airtime_flags field... So don't think anything
> else is needed there either?
> 
> -Toke

Not sure I get this right. Are you talking about local->airtime_flags =
AIRTIME_USE_TX | AIRTIME_USE_RX ? I think that's different and we still
need to take NL80211_EXT_FEATURE_AIRTIME_FAIRNESS into account, right?

Ryder