[Make-wifi-fast] Higher latency on upload under poor signal conditions

[Toke Høiland-Jørgensen]

>> > Is this what I would be looking for (I only included the relevant part of the output)?
>> > $ iw wlp18s0 station dump
>> > tx packets: 742091
>> > tx retries: 417
>> > This is the output after running an upload test and getting pretty
>> > much the same results. I disabled and re-enabled the wireless NIC
>> > before the test since that seems to reset the stats. It doesn't really
>> > look like the retry rate is high, but I don't really know what's
>> > considered high in the first place.
>>
>> That does not seem overly high, no. I guess 80ms could just be queueing
>> delay, either in the firmware, or because your driver is not using
>> TXQs...
>
> It seems like I also have TXQs:
>
> $ iw phy | grep TXQ
> * [ TXQS ]: FQ-CoDel-enabled intermediate TXQs
>
> I guess that it's probably in the firmware then. IIRC I don't see this
> behaviour when I have a good connection, but I'll have to perform a
> test to be sure.

Well, it may be that the firmware is doing a lot of retransmits and not
telling the OS. Or it may simply be that the poor connection ends up
dropping the effective rate so the buffering becomes more noticeable.

-Toke