On 19-9-2016 8:36, Jörg Krause wrote:
> Hi Arend,
> 
> On Wed, 2016-09-14 at 20:13 +0200, Arend Van Spriel wrote:
>> 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 <joerg.krause
>>>>>>>> @emb
>>>>>>>> ed
>>>>>>>> ded.
>>>>>>>> ro
>>>>>>>> cks>
>>>>>>>> wrote:
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> Am 5. August 2016 23:01:10 MESZ, schrieb Arend Van Spriel
>>>>>>>> <
>>>>>>>> arend.vanspr...@broadcom.com>:
>>>>>>>>
>>>>>>>>
>>>>>>>> Op 5 aug. 2016 22:46 schreef "Jörg Krause"
>>>>>>>> <joerg.krause@embedded.rocks>:
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> 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  Cwn
>>>>>>>> d
>>>>>>>>     [  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.
> 
> Did you had some time to look at this?

Ehm. I still only see TCP stuff. To capture 802.11 management frames you
need preferably a dedicated device using monitor mode [1].

Regards,
Arend

[1]
https://wireless.wiki.kernel.org/en/users/documentation/modes#monitor_mode

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