Wi-fi socket buffer size?

[Alex888]

Hi NXP experts,

I would like to how to config the socket buffer size at the driver? I'm using the 88w9098 chip.

I am doing some experiments. I have changed the socket buffer size at the kernel, so I might need also change the buffer size at the Wi-Fi driver side. Could someone tell me how to config/modify the socket buffer size?

Thank you.

[Alex888]

Hi Christine,

Thank you so much. We are using AX 5Ghz 80Mhz in AP mode for UDP.

We are using openWRT kernel v5.4. Is it the same kernel version to yours?

Attached is the hostapd.conf file. Please help to verify at your side.

Thanks.

[Christine_Li]

Hi, @Alex888 

May I ask what's your Wi-Fi driver version and FW version?

I checked the 88W9098 WiFi driver release note, it mentioned that we received and fixed issue that low UDP TX(20-25%) throughout observed on HW-80MHZ Band for all securities.

It has been fixed  on FW 17.92.1.p116.1.

Can you have a try on the latest FW or at lease FW 17.92.1.p116.1?

You can download it from our nxp.com

(https://www.nxp.com/products/wireless/wi-fi-plus-bluetooth-plus-802-15-4/2-4-5-ghz-dual-band-2x2-wi-...

or our FW github

(https://github.com/nxp-imx/imx-firmware/tree/lf-6.1.1_1.0.0/nxp).

Best regards,

Christine.

[Christine_Li]

Hi, @Alex888 

For maximum tx buffer size, you can modify it in wifi_mod_para.conf as below:

 max_tx_buf=2048|4096|8192 <maximum AMSDU Tx buffer size>.

To get the maximum Tx buffer size and current Tx buffer size, you can use below command:

cat /proc/mwlan/adapterX/mlanY|uapY|wfdY/debug.

For more info, please refer to our README_MLAN in driver package. 

Attachment is my test result on 88W9098  for your reference.

Hope above info can help you.

Have a nice day~

Best regards,

Christine.

[Alex888]

Hi Christine,

Thank you for telling us how to adjust the socket buffer size on the wifi side.

Now the problem we encounter is mainly that the 5Ghz wifi DL tput can't go up and can only reach about 520Mb. We use iperf for UDP testing, the environment and cmd are as follows:

Router <- WIFI wireless -> Client PC

Server iperf CMD: iperf -s -u -i1

Client iperf CMD:iperf -i1 -c 192.168.1.139 -u -b1000M -l1472 -p4110 -P30 -t30

We have adjusted the buffer size according to your suggestion, and the test results of adjusting the buffer size are as follows:

1-set up max_tx_buf_size = 2048

->hostapd Setup failed

2-set up max_tx_buf_size = 4096

-> default value, Max. DL tput about 550Mbps

3- set up max_tx_buf_size = 8192

-> Max. DL tput about 450-500Mbps

It has been confirmed that the data sent from the kernel side can reach 650mbps, but the data sent from uap0 on the wifi side is only 520mbps.

In addition to the buffer size of wifi, is there any other reason that will cause the wifi DL tput to be limited (the maximum is 520~550Mbps)?

Thank you

[Christine_Li]

For the throughput data, we can refer to our driver release note.pdf.

It seems like we can achieve 700+ Mbits/s for UDP in 5Ghz 80MHZ ac mode and 800+ Mbits/s for UDP in 5Ghz 80MHZ in AP mode.

Which mode are you using?

Can you please share your hostapd.conf file to me? I can do a test locally tomorrow for you reference.

Best regards,

Christine.