Return-path: Received: from mail-wm0-f43.google.com ([74.125.82.43]:35427 "EHLO mail-wm0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754177AbcINSNM (ORCPT ); Wed, 14 Sep 2016 14:13:12 -0400 Received: by mail-wm0-f43.google.com with SMTP id i130so61983973wmf.0 for ; Wed, 14 Sep 2016 11:13:11 -0700 (PDT) Subject: Re: TCP data throughput for BCM43362 To: =?UTF-8?Q?J=c3=b6rg_Krause?= , Franky Lin References: <1470429980.29489.10.camel@embedded.rocks> <1BCE83A1-AA47-438D-BC47-05AE53D40121@embedded.rocks> <1470492734.2120.0.camel@embedded.rocks> <6cdbbae7-8a56-6778-e886-68eeea7add15@broadcom.com> <1471873052.1683.27.camel@embedded.rocks> <40d15186-6ddf-a210-03de-2bbe21957f1d@broadcom.com> <1472505309.21429.3.camel@embedded.rocks> <1473860503.19492.19.camel@embedded.rocks> Cc: Brett Rudley , brcm80211-dev-list , Hante Meuleman , Franky Lin , linux-wireless@vger.kernel.org, Arend van Spriel From: Arend Van Spriel Message-ID: <27e007ed-57f6-4082-2f65-a11ba3b7f548@broadcom.com> (sfid-20160914_201317_176359_1B8B6255) Date: Wed, 14 Sep 2016 20:13:07 +0200 MIME-Version: 1.0 In-Reply-To: <1473860503.19492.19.camel@embedded.rocks> Content-Type: text/plain; charset=utf-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: On 14-9-2016 15:41, Jörg Krause wrote: > Hi, > > On Mon, 2016-08-29 at 23:15 +0200, Jörg Krause wrote: >> On Mi, 2016-08-24 at 20:35 +0200, Arend Van Spriel wrote: >>> >>> On 22-8-2016 15:37, Jörg Krause wrote: >>>> >>>> >>>> Hi all, >>>> >>>> I am back from vacation and I'd like to do more investigations >>>> about >>>> this issue. Please see my comments below... >>>> >>>> On Sun, 2016-08-07 at 13:41 +0200, Arend van Spriel wrote: >>>>> >>>>> >>>>> On 06-08-16 16:12, Jörg Krause wrote: >>>>>> >>>>>> >>>>>> >>>>>> Hi all, >>>>> >>>>> A bit weird email format making it a bit hard to determine >>>>> where >>>>> your >>>>> last reply starts... >>>>> >>>>>> >>>>>> >>>>>> >>>>>> On Fr, 2016-08-05 at 17:56 -0700, Franky Lin wrote: >>>>>> >>>>>> On Fri, Aug 5, 2016 at 2:29 PM, Jörg Krause >>>>> ed >>>>>> ded. >>>>>> ro >>>>>> cks> >>>>>> wrote: >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> Am 5. August 2016 23:01:10 MESZ, schrieb Arend Van Spriel < >>>>>> arend.vanspriel@broadcom.com>: >>>>>> >>>>>> >>>>>> Op 5 aug. 2016 22:46 schreef "Jörg Krause" >>>>>> : >>>>>> >>>>>> >>>>>> >>>>>> Hi, >>>>>> >>>>>> I'm using a custom ARM board with an BCM43362 wifi chip from >>>>>> >>>>>> Broadcom. >>>>>> >>>>>> >>>>>> The wifi chip is attached via SDIO to the controller with a >>>>>> clock of >>>>>> 48MHz. Linux kernel version is 4.7. >>>>>> >>>>>> When measuring the network bandwidth with iperf3 I get a >>>>>> bandwith of >>>>>> only around 5 Mbps. I found a similar thread at the Broadcom >>>>>> >>>>>> community >>>>>> >>>>>> >>>>>> [1] where the test was done with a M4 CPU + BCM43362 and an >>>>>> average >>>>>> result of 3.3 Mbps. >>>>>> >>>>>> Interestingly, a BCM43362 Wi-Fi Dev Kit [2] notes a TCP data >>>>>> >>>>>> throughput >>>>>> >>>>>> >>>>>> greater than 20 Mbps. >>>>>> >>>>>> Why is the throughput I measured much lower? Note that I >>>>>> measured >>>>>> several times with almost no neighbor devices or networks. >>>>>> >>>>>> This is a test sample measured with iperf3: >>>>>> >>>>>> $ iperf3 -c 192.168.2.1 -i 1 -t 10 >>>>>> Connecting to host 192.168.2.1, port 5201 >>>>>> [ 4] local 192.168.2.155 port 36442 connected to >>>>>> 192.168.2.1 >>>>>> >>>>>> port >>>>>> >>>>>> >>>>>> 5201 >>>>>> [ ID] >>>>>> Interval Transfer Bandwidth Retr Cwnd >>>>>> [ 4] 0.00-1.00 sec 615 KBytes 5.04 >>>>>> Mbits/sec 0 56.6 >>>>>> KBytes >>>>>> [ 4] 1.00-2.00 sec 622 KBytes 5.10 >>>>>> Mbits/sec 0 84.8 >>>>>> KBytes >>>>>> [ 4] 2.00-3.00 sec 625 KBytes 5.12 >>>>>> Mbits/sec 0 113 >>>>>> KBytes >>>>>> [ 4] 3.00-4.00 sec 571 KBytes 4.68 >>>>>> Mbits/sec 0 140 >>>>>> KBytes >>>>>> [ 4] 4.00-5.00 sec 594 KBytes 4.87 >>>>>> Mbits/sec 0 167 >>>>>> KBytes >>>>>> [ 4] 5.00-6.00 sec 628 KBytes 5.14 >>>>>> Mbits/sec 0 195 >>>>>> KBytes >>>>>> [ 4] 6.00-7.00 sec 619 KBytes 5.07 >>>>>> Mbits/sec 0 202 >>>>>> KBytes >>>>>> [ 4] 7.00-8.00 sec 608 KBytes 4.98 >>>>>> Mbits/sec 0 202 >>>>>> KBytes >>>>>> [ 4] 8.00-9.00 sec 602 KBytes 4.93 >>>>>> Mbits/sec 0 202 >>>>>> KBytes >>>>>> [ 4] 9.00-10.00 sec 537 KBytes 4.40 >>>>>> Mbits/sec 0 202 >>>>>> KBytes >>>>>> - - - - - - - - - - - - - - - - - - - - - - - - - >>>>>> [ ID] >>>>>> Interval Transfer Bandwidth Retr >>>>>> [ 4] 0.00-10.00 sec 5.88 MBytes 4.93 >>>>>> Mbits/sec 0 sender >>>>>> [ 4] 0.00-10.00 sec 5.68 MBytes 4.76 >>>>>> Mbits/sec receiver >>>>>> >>>>>> >>>>>> Not overly familiar with iperf3. Do these lines mean you are >>>>>> doing >>>>>> bidirectional test, ie. upstream and downstream at the same >>>>>> time. >>>>>> Another >>>>>> thing affecting tput could be power-save. >>>>>> >>>>>> >>>>>> No, iperf3 does not support bidrectional test. Power-save is >>>>>> turned >>>>>> off. >>>>>> >>>>>> What does iw link say? >>>>>> >>>>> >>>>> but I guess it starts here! >>>>> >>>>>> >>>>>> >>>>>> >>>>>> I compared the results with a Cubietruck I have: >>>>>> >>>>>> # iperf3 -s >>>>>> ----------------------------------------------------------- >>>>>> Server listening on 5201 >>>>>> ----------------------------------------------------------- >>>>>> Accepted connection from 192.168.178.46, port 42906 >>>>>> [ 5] local 192.168.178.38 port 5201 connected to >>>>>> 192.168.178.46 >>>>>> port >>>>>> 42908 >>>>>> [ ID] Interval Transfer Bandwidth >>>>>> [ 5] 0.00-1.00 sec 2.29 MBytes 19.2 >>>>>> Mbits/sec >>>>>> [ 5] 1.00-2.00 sec 2.21 MBytes 18.5 >>>>>> Mbits/sec >>>>>> [ 5] 2.00-3.00 sec 2.17 MBytes 18.2 >>>>>> Mbits/sec >>>>>> [ 5] 3.00-4.00 sec 2.09 MBytes 17.6 >>>>>> Mbits/sec >>>>>> [ 5] 4.00-5.00 sec 2.20 MBytes 18.5 >>>>>> Mbits/sec >>>>>> [ 5] 5.00-6.00 sec 2.64 MBytes 22.1 >>>>>> Mbits/sec >>>>>> [ 5] 6.00-7.00 sec 2.67 MBytes 22.4 >>>>>> Mbits/sec >>>>>> [ 5] 7.00-8.00 sec 2.62 MBytes 22.0 >>>>>> Mbits/sec >>>>>> [ 5] 8.00-9.00 sec 2.35 MBytes 19.8 >>>>>> Mbits/sec >>>>>> [ 5] 9.00-10.00 sec 2.30 MBytes 19.3 >>>>>> Mbits/sec >>>>>> [ 5] 10.00-10.03 sec 83.4 KBytes 23.5 >>>>>> Mbits/sec >>>>>> - - - - - - - - - - - - - - - - - - - - - - - - - >>>>>> [ ID] Interval Transfer Bandwidth Retr >>>>>> [ 5] 0.00-10.03 sec 23.9 MBytes 20.0 >>>>>> Mbits/sec 0 sender >>>>>> [ 5] 0.00-10.03 sec 23.6 MBytes 19.8 >>>>>> Mbits/sec receiver >>>>>> >>>>>> # iw dev wlan0 link >>>>>> Connected to xx:xx:xx:xx:xx (on wlan0) >>>>>> SSID: xxx >>>>>> freq: 2437 >>>>>> tx bitrate: 65.0 MBit/s >>>>>> >>>>>> bss flags: short-preamble short-slot-time >>>>>> dtim period: 1 >>>>>> beacon int: 100 >>>>> >>>>> Too bad RSSI is not in the output above. That may be due to a >>>>> regression >>>>> in our driver which has been fixed by commit 94abd778a7bb >>>>> ("brcmfmac: >>>>> add fallback for devices that do not report per-chain values"). >>>>> However, >>>>> the tx bitrate seems within the same range as the other >>>>> platform. >>>>> >>>>>> >>>>>> >>>>>> >>>>>> The Cubietruck works also with the brcmfmac driver. >>>>>> >>>>>> May it depend on the NVRAM file? >>>>> >>>>> Not sure. Can you tell me a bit more about the custom ARM >>>>> board. >>>>> Does >>>>> it >>>>> use the same wifi module as Cubietruck, ie. the AMPAK AP6210? >>>>> If >>>>> you >>>>> can >>>>> make a wireshark sniff we can check the actual bitrate and >>>>> medium >>>>> density in terms of packets. Another thing to look at is the >>>>> SDIO >>>>> host >>>>> controller. In brcmf_sdiod_sgtable_alloc() some key values are >>>>> used >>>>> from >>>>> the host controller. It only logs the number of entries of the >>>>> scatter-gather table, but could you add the other values in >>>>> this >>>>> function that are used to determine the number of entries. >>>> >>>> My board uses the BCM43362 chip solely (no Bluetooth) attached to >>>> the >>>> SDIO interface of a NXP i.MX28 processor. >>>> >>>> I added some additional printk() to brcmf_sdiod_sgtable_alloc(). >>>> These >>>> are the values printed after modprobe brcmfmac: >>>> >>>> [ 8.926657] sg_support=1 >>>> [ 8.929440] max_blocks=511 >>>> [ 8.932213] max_request_size=261632 >>>> [ 8.935741] max_segment_count=52 >>>> [ 8.939005] max_segment_size=65280 >>>> [ 8.946095] nents=35 >>> >>> Thanks. That looks good. >>> >>>> >>>> >>>> Additionally I attached a xz compresses wireshark sniff while >>>> running >>>> iper3 between the BCM43362 running as in AP mode with iperf3 as a >>>> server and a PC in station mode running iperf3 as a client. >>> >>> Looking at the sniff it seems you captured on the ethernet side. >>> That >>> does not give me any 802.11 specific info. Can you make a wireless >>> capture preferably without encryption. >> >> You,re right! Sorry for this mistake. I did a re-capture on the >> wireless side now. > > Anything new about this? Anything I can do to help? I missed your previous email. Was already wondering whether to ping you. Digging around in my email folders I found it so will take a look at it. Regards, Arend