From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from [208.74.158.174] (helo=mail3.candelatech.com) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hRMrT-0007G4-RY for ath10k@lists.infradead.org; Thu, 16 May 2019 20:20:21 +0000 Subject: Re: Problem with 9984 in routed mode with 512b frames. References: <10ed4e39-4364-c8ef-2b38-15ea7672ad94@candelatech.com> <2ec6f626-6391-f9b5-918c-99ad7e6b3e31@newmedia-net.de> <55b50a9a-49f4-d669-22d4-84e2efabf451@candelatech.com> From: Ben Greear Message-ID: <958466d1-2d3a-d1cd-e1f6-65e032f15e15@candelatech.com> Date: Thu, 16 May 2019 13:20:18 -0700 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "ath10k" Errors-To: ath10k-bounces+kvalo=adurom.com@lists.infradead.org To: Adrian Chadd Cc: Sebastian Gottschall , ath10k On 5/16/19 1:16 PM, Adrian Chadd wrote: > You can't do AMPDU with OFDM/CCK. If they're setting the AMPDU bit > then that's wrong. it needs to be individual MPDU/PPDUs. > > There's a benefit for CCK. OFDM 6M is I think roughly the same as OFDM > MCS0. But CCK is a lot more reliable. 5Ghz can (should) not do CCK anyway. Do you have any reference for why you think CCK will be better? The one I found shows otherwise: https://d2cpnw0u24fjm4.cloudfront.net/wp-content/uploads/LaminatedCard_RevolutionWiFiMCStoSNRSinglePage.png Thanks, Ben > > > -adrian > > On Thu, 16 May 2019 at 13:10, Ben Greear wrote: >> >> On 5/16/19 12:55 PM, Adrian Chadd wrote: >>> You can totally go down to OFDM yeah but you then need to send it at >>> 20MHz and non-AMPDU. >>> >>> Is it maybe the retry code + rate control code is retagging an AMPDU >>> at a lower rate and it's transitioning down to CCK/OFDM without >>> breaking the AMPDU apart? >> >> It was sending a one-frame AMPDU, and one frame AMSDU for that matter. Maybe >> there is some bit in the tx descriptor that needed to be twiddled as well >> to make OFDM able to work, but I don't know what that would be. >> >> Is there any advantage of (any) OFDM over MCS0 HT 20Mhz as far as range or >> SNR goes? The chart I found made it look like there was not, and if >> not, then why bother at all with OFDM if peer advertises HT/VHT rates? >> >> Thanks, >> Ben >> >>> >>> >>> -a >>> >>> On Thu, 16 May 2019 at 12:40, Ben Greear wrote: >>>> >>>> On 5/15/19 6:00 AM, Ben Greear wrote: >>>>> On 5/15/19 5:26 AM, Sebastian Gottschall wrote: >>>>>> >>>>>> Am 15.05.2019 um 14:20 schrieb Ben Greear: >>>>>>> On 05/14/2019 09:26 PM, Sebastian Gottschall wrote: >>>>>>>> can you send me a detailed instruction for testing this on my devices? so which commands have been used for generating the traffic etc. (iperf3?) >>>>>>> >>>>>>> I am using our own traffic generator, but I imagine iperf3 should work fine too. >>>>>>> >>>>>>> I am testing on x86-64 and so forth. Maybe you can test with UDP small-packet load on your platform >>>>>>> in routed mode (ie, external iperf generator through your AP) and see if you see issues? >>>>>> thats the plan. can you do a test with iperf3 to see if its reproduceable. i mean i will test it on ipq based boards and x64. but to make sure that the scenario >>>>>> is identical which raised up your issue, it would be find if we have identical software for testing including the same options >>>> >>>> I think I found the issue. The rate-ctrl logic in the firmware allows a transition from HT/VHT 20 MCS0 down to OFDM rates. >>>> It seems the hardware does not like to see an AMPDU with an OFDM rate for 20Mhz and a VHT rate for 80Mhz (or maybe just the >>>> single OFDM rate is the fault). >>>> >>>> If you can edit firmware, then setting this to 0 probably fixes the issue. >>>> >>>> g_rc_cck_rate_allowed >>>> >>>> I think to reproduce you'd need to send high speed traffic in a situation where the >>>> RF environment is going to make rate-ctrl fail quite a bit. (Slow speed should >>>> work too, but it would likely take a lot longer). >>>> >>>> And, it is always possible that whatever I saw when testing mostly-stock FW is different >>>> from what I eventually debugged to in my firmware. Still, from looking at MCS vs SNR >>>> charts, there seems to be no advantage to trying OFDM vs MCS0 for 20Mhz. >>>> >>>> Thanks, >>>> Ben >>>> >>>> -- >>>> Ben Greear >>>> Candela Technologies Inc http://www.candelatech.com >>>> >>>> >>>> _______________________________________________ >>>> ath10k mailing list >>>> ath10k@lists.infradead.org >>>> http://lists.infradead.org/mailman/listinfo/ath10k >>> >> >> >> -- >> Ben Greear >> Candela Technologies Inc http://www.candelatech.com >> >> >> _______________________________________________ >> ath10k mailing list >> ath10k@lists.infradead.org >> http://lists.infradead.org/mailman/listinfo/ath10k > -- Ben Greear Candela Technologies Inc http://www.candelatech.com _______________________________________________ ath10k mailing list ath10k@lists.infradead.org http://lists.infradead.org/mailman/listinfo/ath10k