Re: [PATCH] wifi: mt76: mt7603: discard power-save loopbacks after wakeup

[Felix Fietkau <nbd@nbd.name>]

On 14.10.26 08:22, Cristian Papa wrote:
> A station wakeup drains its power-save queue once, while frames
> redirected by the PSE can still be waiting on the MCU RX ring. Processing
> those loopbacks after the wakeup queues them for an already awake station
> and sets the driver's buffered indication again. The stale frames remain
> queued until another service period or sleep/wake transition drains them.
> 
> Check ps_sleeping under ps_lock before buffering a loopback, and publish
> the buffered indication under the same lock. The wakeup's state change
> and queue drain use that lock too, so late frames cannot repopulate the
> queue or leave a stale buffered indication after the wakeup.
> 
> Discard late frames rather than retransmitting their old sequence and
> packet numbers after newer traffic or a wakeup BAR. This loses the late
> frame; it does not recover delivery. Use the station's sleep state, not
> the temporary hardware PS bypass used during U-APSD service periods.
Why did you decide to drop them instead of pushing them to immediate tx?

- Felix