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@embedded.
> > ro
> > cks>
> > wrote:
> >
> >
> >
> >
> >
> > Am 5. August 2016 23:01:10 MESZ, schrieb Arend Van Spriel <
> > arend.vanspriel@xxxxxxxxxxxx>:
> >
> >
> > 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 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
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.
Best regards
Jörg Krause
Attachment:
bcm43362.pcapng.xz
Description: application/xz
