Return-path: Received: from mail-qt0-f175.google.com ([209.85.216.175]:37584 "EHLO mail-qt0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729902AbeGZOTl (ORCPT ); Thu, 26 Jul 2018 10:19:41 -0400 Received: by mail-qt0-f175.google.com with SMTP id n6-v6so1409190qtl.4 for ; Thu, 26 Jul 2018 06:02:54 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <87zhye1aqg.fsf@toke.dk> References: <1532589677-16428-1-git-send-email-wgong@codeaurora.org> <1532589677-16428-3-git-send-email-wgong@codeaurora.org> <87zhye1aqg.fsf@toke.dk> From: =?UTF-8?Q?Micha=C5=82_Kazior?= Date: Thu, 26 Jul 2018 15:02:53 +0200 Message-ID: (sfid-20180726_150257_466520_5B823EC4) Subject: Re: [PATCH 2/2] ath10k: Set sk_pacing_shift to 6 for 11AC WiFi chips To: =?UTF-8?B?VG9rZSBIw7hpbGFuZC1Kw7hyZ2Vuc2Vu?= Cc: Wen Gong , ath10k@lists.infradead.org, Johannes Berg , linux-wireless Content-Type: text/plain; charset="UTF-8" Sender: linux-wireless-owner@vger.kernel.org List-ID: On 26 July 2018 at 13:45, Toke H=C3=B8iland-J=C3=B8rgensen w= rote: > Wen Gong 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? Micha=C5=82