On 26 July 2018 at 13:45, Toke Høiland-Jørgensen <toke@xxxxxxx> wrote: > Wen Gong <wgong@xxxxxxxxxxxxxx> writes: > >> Upstream kernel has an interface to help adjust sk_pacing_shift to help >> improve TCP UL throughput. >> The sk_pacing_shift is 8 in mac80211, this is based on test with 11N >> WiFi chips with ath9k. For QCA6174/QCA9377 PCI 11AC chips, the 11AC >> VHT80 TCP UL throughput testing result shows 6 is the optimal. >> Overwrite the sk_pacing_shift to 6 in ath10k driver. > > When I tested this, a pacing shift of 8 was quite close to optimal as > well for ath10k. Why are you getting different results? > >> Tested with QCA6174 PCI with firmware >> WLAN.RM.4.4.1-00109-QCARMSWPZ-1, but this will also affect QCA9377 PCI. >> It's not a regression with new firmware releases. >> >> There have 2 test result of different settings: >> >> ARM CPU based device with QCA6174A PCI with different >> sk_pacing_shift: Different firmware releases have different tx buffering characteristics. In some 10.2 firmware running on QCA9888 you can have up to 5ms of delayed aggregation. Ideally sk_pacing_shift should be adjusted per firmware release. Maybe this should become part of the ath10k firmware wrapping "fw features" stuff? Michał
