Hi Roman, On 22 April 2016 at 19:05, Roman Yeryomin <leroi.li...@gmail.com> wrote: > On 19 April 2016 at 18:35, Valo, Kalle <kv...@qca.qualcomm.com> wrote: >> Michal Kazior <michal.kaz...@tieto.com> writes: >> >>> On 19 April 2016 at 09:31, Roman Yeryomin <leroi.li...@gmail.com> wrote: >>>> On 19 April 2016 at 08:28, Michal Kazior <michal.kaz...@tieto.com> wrote: >>>> >>>>> If my hunch is right there's no easy (and proper) fix for that now. >>>>> >>>>> One of the patchset patches (ath10k: implement wake_tx_queue) starts >>>>> to use mac80211 software queuing. This introduces extra induced >>>>> latency and I'm guessing it results in fill-in-then-drain sequences in >>>>> some cases which end up being long enough to make fq_codel_drop more >>>>> work than normal. >>>>> >>>>> This is required for other changes and MU-MIMO performance >>>>> improvements so this patch can't be removed. >>>> >>>> But qca988x doesn't support MU-MIMO, AFAIK. >>> >>> Correct. >>> >>> >>>> Can this be made chip dependent? >>> >>> I guess it could but it'd arguably make the driver more complex and >>> harder to maintain. What we want is a long-term fix, not a short-term >>> one. >> >> But we should never go backwards and TCP dropping from 750 Mbps to ~550 >> Mbps is a huge drop, so this is not ok. We have to do something to fix >> this, be it reverting the wake_tx_queue support, somehow disabling it by >> default or something. > > I would agree with Kalle here. This looks like very serious regression. > But I'm afraid I can only help with testing here.
Can you give the following patch a try, please? I didn't get to reproduce your problem on a real AP135/AP152 board and instead tried to simulate a slow uni-proc system via KVM and cooling_device in sysfs. The patch does improve things in this synthetic setup for me. http://lists.infradead.org/pipermail/ath10k/2016-May/007526.html MichaĆ _______________________________________________ ath10k mailing list ath10k@lists.infradead.org http://lists.infradead.org/mailman/listinfo/ath10k