How to achieve maximum throughput using iperf3?

Technical Support
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1

Hi all,

We are using Apalis iMX6Q SoM on Apalis Evaluation V1.1A board. Using this combination for our SDIO3.0 board with WiFi capabilities which supports high throughput of 330Mbps.

Currently we get only ~50Mbps. So how can we achieve maximum throughput?

Thanks,
Sridhar

2

hi @sridhar.jonnavittula

Could you provide the complete dmesg log in a file? What is the output of lsmod?

How are you testing the SDIO Wifi Card?
What is the chipset of the Wifi Card?
Could you provide details about your Setup (Which Router, Distance to Router, Antenna)?

Could you check also for the output of cat /sys/kernel/debug/mmcX/ios , where X is a number representing your SDIO wifi card?

Thanks and best regards,
Jaski

3

Hi,
We have tested the data throughputs on Colibri iMX7 board and getting good throughputs (Tx=85.2 , Rx=104).

Also tested on the Freescale IMXSX Sabre SD board and observed throughputs (Tx: 60 and Rx: 100) close to Colibri.

The same driver and WiFi card on Apalis is not performing well. It’s inconsistent and going to 0’s (iperf test) also sometimes.

What could be the problem? Is it the SD slot issue or any other issue with Apalis. Please help to debug this issue.

4

Hi @sridhar.jonnavittula

Thanks for the input. Could you answer my questions from the previous post?

Best regards,
Jaski

5

Could you check also for the output of cat /sys/kernel/debug/mmcX/ios , where X is a number representing your SDIO wifi card?

cat /sys/kernel/debug/mmc2/ios

clock:          50000000 Hz
actual clock:   49500000 Hz
vdd:            21 (3.3 ~ 3.4 V)
bus mode:       2 (push-pull)
chip select:    0 (don't care)
power mode:     2 (on)
bus width:      2 (4 bits)
timing spec:    2 (sd high-speed)
signal voltage: 0 (3.30 V)
driver type:    0 (driver type B)

Could you provide details about your Setup (Which Router, Distance to Router, Antenna)?

Router: Dlink DIR-825
Distance: 2meters
Antenna on our 1x1 SDIO card: two flag antennas
Operating in 11n mode 5GHz

What is the chipset of the Wifi Card?
Qualcomm SDIO3.0 WiFi card

How are you testing the SDIO Wifi Card?
Just connected in above mode and running normal iperf3

What is the output of lsmod?

wlan                 4752576  0
bluetooth             310865  2
usb_f_rndis            11166  2
u_ether                 8661  1 usb_f_rndis
ov5640_camera_mipi_int    21592  0
mxc_v4l2_capture       25556  1 ov5640_camera_mipi_int
ipu_bg_overlay_sdc      5297  1 mxc_v4l2_capture
ipu_still               1763  1 mxc_v4l2_capture
ipu_prp_enc             5763  1 mxc_v4l2_capture
ipu_csi_enc             3417  1 mxc_v4l2_capture
ipu_fg_overlay_sdc      5936  1 mxc_v4l2_capture
adv7280_tvin            6681  0
max9526_tvin            5870  0
v4l2_int_device         1883  4 ov5640_camera_mipi_int,adv7280_tvin,max9526_tvin,mxc_v4l2_capture
cfg80211              252860  1 wlan
libcomposite           34201  10 usb_f_rndis
configfs               23726  3 usb_f_rndis,libcomposite
galcore               366496  4

Attached complete dmesg in log file.
kernel boot up log

6

And what ios does the Colibri iMX7 report? You may be aware that while the Colibri iMX7 may actually support higher speed UHS-I signaling modes requiring a 1.8 volt signaling voltage, the Apalis iMX6 unfortunately does not as that voltage rail may not be switchable. That said, it still should support regular 50 MHz mode totaling raw 200 Mbit. However, please check your SDIO device spec whether or not and in what exact mode it may support any such. Your description may also point to an entirely different issue. Maybe you need continues clocking activated?

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Q: And what ios does the Colibri iMX7 report?
A:

  1. clock: 196363636 Hz
  2. actual clock: 196363636 Hz
  3. vdd: 21 (3.3 ~ 3.4 V)
  4. bus mode: 2 (push-pull)
  5. chip select: 0 (don’t care)
  6. power mode: 2 (on)
  7. bus width: 2 (4 bits)
  8. timing spec: 6 (sd uhs SDR104)
  9. signal voltage: 1 (1.80 V)
  10. driver type: 0 (driver type B)

Q: Your description may also point to an entirely different issue. Maybe you need continues clocking activated?
A: Are you telling this based on clock and actual clock values in ios report?

Maybe you need continues clocking activated?
What should be done for this on Apalis and WiFi card?

Attached colibri full dmesg log for reference.Colibri iMX7 emmc dmesg log.

When I try to load driver for wlan interface at this [562.996053] time the MMC stack is returning error -110 and I cannot use my WiFi card.

Can you please take a look and point how to proceed to make use of WiFI card?
It will be very helpful for us.

8

Hi

Thanks for this Information

A: Are you telling this based on clock and actual clock values in ios report?

No, the answer refers to Apalis iMX6, which is not able to switch the sd clock signal voltage to 1.8V. So you need to find out if your SDIO card can operate at higher frequencies than 50MHz with 3.3V.

When I try to load driver for wlan interface at this [562.996053] time the MMC stack is returning error -110 and I cannot use my WiFi card.

Is this a new Wifi Card, since you made tests where you achieved good results?

Best regards,
Jaski