(need help) Bluetooth scan / connection failed if WiFi is ON

[ffongmdsp]

Hello,

I updated to the latest 8821cu driver (14798a1f917383acef2d8b3f7b40acaa64b5f5ef). Now it is great to see the latest dongle works. Wi-Fi and Bluetooth works but only separately:

• Bluetooth scan fails to find any devices unless I turned off the Wi-Fi interface.
• Bluetooth connection will be dropped as soon as I turned on the Wi-Fi interface.

The system is Linux 5.4.75. The hardware is EDUP USB Dongle. I could provide more details is needed.

Note: an older version of the dongle does not have this problem. (It is a version where it appears as USB Mass-Storage when inserted, requires usb-modeswitch to turn it into NIC).

The hardware platform is Nanopi Neo3 (Rockchip RK3328)

sudo uname -a; sudo mokutil --sb-state; lsusb; sudo rfkill list all; sudo dkms status; sudo iw dev Linux shd119ota 5.4.75+ #2 SMP Fri Apr 9 12:35:58 CEST 2021 aarch64 GNU/Linux sudo: mokutil: command not found Bus 005 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 004 Device 002: ID 0bda:c820 Realtek Semiconductor Corp. Bus 004 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub 2: hci0: Bluetooth Soft blocked: no Hard blocked: no 3: phy1: Wireless LAN Soft blocked: no Hard blocked: no sudo: dkms: command not found phy#1 Interface wlan0 ifindex 4 wdev 0x100000001 addr e8:4e:06:98:c5:6b ssid ASUS-d4 type managed channel 40 (5200 MHz), width: 80 MHz, center1: 5210 MHz

[morrownr]

Hi @ffongmdsp

I'm going to mark this issue as needs help so if anyone else that may have a solution comes by, they may see it better.

I'm at a disadvantage in that my 8811cu adapter does not have BT capability so it is impossible for me to attempt to duplicate the problem. Also, my to-do list is long right now. I will take a look at I can.

Separate subject: How did you handle step 9 of the installation steps. That Rockchip is ARM based, correct?

Regards

[ffongmdsp]

Hello @morrownr,

Thanks for your feedbacks.

1. Regarding how I configure to compile for the Rockchip Platform (Step-9) - instead of DKMS, I simply run the Makefile passing in some variable values: make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- KSRC=<Path to my Rockhip kernel source>

2. I could send you a EDUP Dongle (WiFi + BT) for reference if that helps.

3. Feel free to let me know if you would like to experiment changes of the code. I could do this here for you.

Thanks Frankie

[morrownr]

Hi @ffongmdsp

I could send you a EDUP Dongle (WiFi + BT) for reference if that helps.

I may have a 8822bu adapter headed my way from another source so I may be able to sort this out with 88x2bu driver. Thanks for the offer but let me take a rain check for now as I am so far behind on my to-do list that this could be something I don't get to for a while.

Regards

[ffongmdsp]

Thanks for the update. I investigated a little further. I built the Realtek driver and run on Raspberry Pi 3B. There is no such problem. That RPi image is using 5.4.79+ Linux kernel with BlueZ 5.50. I am trying to follow this configuration on my Nanopi. I tried BlueZ 5.50 on it but problem persists. I am currently seeking support to have the same kernel version running on the Nanopi. Will see how it goes.

[ffongmdsp]

Here is an update. I have upgraded my nanopi system to 5.4.79+ Linux Kernel and BlueZ 5.50 - exactly matching those version to my Raspberry Pi. But same problem remains. I compared the 8821 logs (captured with rtw_drv_log_level=6). I don't see any obvious difference so far. And I did look for outputs related to Bluetooth Coexistence. And this line appears in nanopi log: EEPROM Disable BT-coex by hal_spec However, the same line appears in Raspberry Pi also.

[morrownr]

Explain to me what BlueZ 5.50 is.

[ffongmdsp]

Explain to me what BlueZ 5.50 is.

BlueZ is a user-space Bluetooth stack. 5.5.0 is the version number. I think it is the most widely used Bluetooth interface in Linux application. It provides various utilities for user to manage Bluetooth adapter, to discover, pair, connect to various Bluetooth devices.
http://www.bluez.org/

I mentioned this because this is the main dependency for my application in terms of using the Bluetooth function of the 8821cu-based USB dongle. My nanopi was using v5.23 before my attempt to match the Raspberry Pi which hosts v5.50.

Hope this helps.