Unable to initialize on STM32F103RE + Quectel EC21 using BG9x driver

[ycsin]

Describe the bug
I'm trying the Quectel BG9x modem driver on my STM32F1 custom board with Quectel EC21 as their initialization should be the same and the offloaded TCP AT commands are the same.

I compiled the modem on basic/blinky example with these

prj.conf

CONFIG_GPIO=y
CONFIG_LOG=y
CONFIG_KERNEL_LOG_LEVEL_DBG=y
CONFIG_KERNEL_LOG_LEVEL_DBG=y
CONFIG_MODEM_LOG_LEVEL_DBG=y

def_config

# Modem
CONFIG_TEST_RANDOM_GENERATOR=y
CONFIG_NETWORKING=y
CONFIG_NET_SOCKETS=y
CONFIG_MODEM=y
CONFIG_MODEM_QUECTEL_BG9X=y

.dts:

    /* QUECTEL EC21 */
    quectel_ec21: quectel_ec21 {
        compatible = "quectel,bg9x";
        label = "QUECTEL EC21";
        mdm-power-gpios = <&gpiob 1 GPIO_ACTIVE_LOW>;
        mdm-reset-gpios = <&gpiob 0 GPIO_ACTIVE_LOW>;
        mdm-dtr-gpios = <&gpioa 15 GPIO_ACTIVE_LOW>;
        status = "okay";
    };

The driver initialized fine, however it seems to be stucked in a bootloop:

Log:

[00:00:00.000,000] <dbg> os.setup_thread_stack: stack 0x20003d60 for thread 0x20001ba8: obj_size=1024 buf_start=0x20003d60  buf_size 1024 stack_ptr=0x20004160
[00:00:00.000,000] <dbg> os.setup_thread_stack: stack 0x20004160 for thread 0x20001b30: obj_size=256 buf_start=0x20004160  buf_size 256 stack_ptr=0x20004260
[00:00:00.000,000] <dbg> os.setup_thread_stack: stack 0x200023c8 for thread 0x20000af0: obj_size=768 buf_start=0x200023c8  buf_size 768 stack_ptr=0x200026c8
[00:00:00.000,000] <dbg> os.setup_thread_stack: stack 0x20004a60 for thread 0x20001c20: obj_size=1024 buf_start=0x20004a60  buf_size 1024 stack_ptr=0x20004e60
[00:00:02.000,000] <dbg> os.setup_thread_stack: stack 0x20002ad0 for thread 0x20001808: obj_size=2048 buf_start=0x20002ad0  buf_size 2048 stack_ptr=0x200032d0
[00:00:02.000,000] <dbg> os.setup_thread_stack: stack 0x200026c8 for thread 0x20001790: obj_size=1032 buf_start=0x200026c8  buf_size 1032 stack_ptr=0x20002ad0
[00:00:02.000,000] <inf> modem_quectel_bg9x: Setting Modem Pins
[00:00:04.750,000] <inf> modem_quectel_bg9x: ... Done!
[00:00:04.750,000] <inf> modem_quectel_bg9x: Waiting for modem to respond
[00:00:13.729,000] <dbg> modem_cmd_handler.cmd_handler_process_rx_buf: match cmd [RDY] (len:3)
[00:00:13.747,000] <dbg> modem_cmd_handler.cmd_handler_process_rx_buf: match cmd [OK] (len:2)
[00:00:13.800,000] <dbg> modem_cmd_handler.cmd_handler_process_rx_buf: match cmd [OK] (len:2)
[00:00:13.883,000] <dbg> modem_cmd_handler.cmd_handler_process_rx_buf: match cmd [OK] (len:2)
[00:00:13.953,000] <dbg> modem_cmd_handler.cmd_handler_process_rx_buf: match cmd [] (len:7)
[00:00:13.953,000] <inf> modem_quectel_bg9x: Manufacturer: Quectel
[00:00:13.954,000] <dbg> modem_cmd_handler.cmd_handler_process_rx_buf: match cmd [OK] (len:2)
[00:00:14.006,000] <dbg> modem_cmd_handler.cmd_handler_process_rx_buf: match cmd [] (len:4)
[00:00:14.006,000] <inf> modem_quectel_bg9x: Model: EC21
[00:00:14.007,000] <dbg> modem_cmd_handler.cmd_handler_process_rx_buf: match cmd [OK] (len:2)
[00:00:14.060,000] <dbg> modem_cmd_handler.cmd_handler_process_rx_buf: match cmd [] (len:16)
[00:00:14.060,000] <inf> modem_quectel_bg9x: Revision: EC21EFAR06A01M4G
[00:00:14.060,000] <dbg> modem_cmd_handler.cmd_handler_process_rx_buf: match cmd [OK] (len:2)
[00:00:14.131,000] <dbg> modem_cmd_handler.cmd_handler_process_rx_buf: match cmd [] (len:15)
[00:00:14.131,000] <inf> modem_quectel_bg9x: IMEI: 867962045083204
[00:00:14.132,000] <dbg> modem_cmd_handler.cmd_handler_process_rx_buf: match cmd [OK] (len:2)
[00:00:14.205,000] <dbg> modem_cmd_handler.cmd_handler_process_rx_buf: match cmd [OK] (len:2)
[00:00:14.207,000] <dbg> modem_cmd_handler.cmd_handler_process_rx_buf: match cmd [+CSQ: ] (len:11)
[00:00:14.207,000] <inf> modem_quectel_bg9x: RSSI: -1000
[00:00:14.208,000] <dbg> modem_cmd_handler.cmd_handler_process_rx_buf: match cmd [OK] (len:2)
[00:00:16.213,000] <dbg> modem_cmd_handler.cmd_handler_process_rx_buf: match cmd [+CSQ: ] (len:11)
[00:00:16.213,000] <inf> modem_quectel_bg9x: RSSI: -1000
[00:00:16.214,000] <dbg> modem_cmd_handler.cmd_handler_process_rx_buf: match cmd [OK] (len:2)
[00:00:18.217,000] <dbg> modem_cmd_handler.cmd_handler_process_rx_buf: match cmd [+CSQ: ] (len:11)
[00:00:18.217,000] <inf> modem_quectel_bg9x: RSSI: -1000
[00:00:18.217,000] <dbg> modem_cmd_handler.cmd_handler_process_rx_buf: match cmd [OK] (len:2)
[00:00:20.220,000] <dbg> modem_cmd_handler.cmd_handler_process_rx_buf: match cmd [+CSQ: ] (len:11)
[00:00:20.220,000] <inf> modem_quectel_bg9x: RSSI: -57
[00:00:20.220,000] <dbg> modem_cmd_handler.cmd_handler_process_rx_buf: match cmd [OK] (len:2)
[00:00:00.000,000] <dbg> os.setup_thread_stack: stack 0x20003d60 for thread 0x20001ba8: obj_size=1024 buf_start=0x20003d60  buf_size 1024 stack_ptr=0x20004160
[00:00:00.000,000] <dbg> os.setup_thread_stack: stack 0x20004160 for thread 0x20001b30: obj_size=256 buf_start=0x20004160  buf_size 256 stack_ptr=0x20004260
[00:00:00.000,000] <dbg> os.setup_thread_stack: stack 0x200023c8 for thread 0x20000af0: obj_size=768 buf_start=0x200023c8  buf_size 768 stack_ptr=0x200026c8
[00:00:00.000,000] <dbg> os.setup_thread_stack: stack 0x20004a60 for thread 0x20001c20: obj_size=1024 buf_start=0x20004a60  buf_size 1024 stack_ptr=0x20004e60
[00:00:02.000,000] <dbg> os.setup_thread_stack: stack 0x20002ad0 for thread 0x20001808: obj_size=2048 buf_start=0x20002ad0  buf_size 2048 stack_ptr=0x200032d0
[00:00:02.000,000] <dbg> os.setup_thread_stack: stack 0x200026c8 for thread 0x20001790: obj_size=1032 buf_start=0x200026c8  buf_size 1032 stack_ptr=0x20002ad0

After this it will repeat again at the

[00:00:02.000,000] <inf> modem_quectel_bg9x: Setting Modem Pins

continuously. If I add a 5 seconds delay after bg9x:L1070, then it will be able to print an additional line:

[00:00:17.080,000] <inf> modem_quectel_bg9x: Network is ready.

I then debugged this and found that it resets at around

or

But then I don't know what to do to further trace this issue down. No errors printed in the log.

To Reproduce
Steps to reproduce the behavior:

1. Build samples/blinky example with the dts, def_config and prj.conf on a STM32F103RE board with Quectel EC21
2. See error

Expected behavior
I'm expecting that LED to be blinking on samples/blinky

Impact
This is a showstopper, I'm working on a IoT device that depends on modem to send data.

Logs and console output
See above

Environment (please complete the following information):

• OS: Windows 10
• Toolchain: gnuarmemb
• Just did west init zephyr_project and west update today, should be the latest version

Additional context
I edited bg9x.h:L33 from 30 to 10 to reduce the amount of SRAM used by the buffer

The log is from my PR, using the original code produced more or less the same result.

[galak]

@bwasim can you help with this.

[bwasim]

The stack trace in your screenshot shows Zephyr Native Networking function calls, which isn't needed when you're using an offloaded driver like quectel-bg9x. So as a first pass, can you please update your configuration to include these options:

# Quectel BG9x modem
CONFIG_MODEM=y
#CONFIG_MODEM_SHELL=y
CONFIG_MODEM_QUECTEL_BG9X=y

# Networking (required for modem)
CONFIG_NETWORKING=y
CONFIG_NET_NATIVE=n
CONFIG_NET_IPV4=y
CONFIG_NET_IPV6=n
CONFIG_NET_SOCKETS=y
CONFIG_NET_SOCKETS_OFFLOAD=y

This doesn't directly fix whatever problem you're seeing, but tries to bypass it as you don't need native networking stack. Should help resolve the problem.

[ycsin]

Quectel BG9x modem

CONFIG_MODEM=y
#CONFIG_MODEM_SHELL=y
CONFIG_MODEM_QUECTEL_BG9X=y

Networking (required for modem)

CONFIG_NETWORKING=y
CONFIG_NET_NATIVE=n
CONFIG_NET_IPV4=y
CONFIG_NET_IPV6=n
CONFIG_NET_SOCKETS=y
CONFIG_NET_SOCKETS_OFFLOAD=y

I'm building this now

EDIT: I can confirm that this 'fixed' the issue, at least it initialized successfully and the LED is blinking now. Thanks!

[bwasim]

Great, I would like to get some feedback on how well this driver works with the EC21 modem. When I initially wrote it, I primarily looked only at the BG95 guide, but found that the BG96 TCP commands are the same. Hence named the driver, "quectel-bg9x".

I haven't looked at the EC21 guides, but if it works well (even with minor modifications), we may want to incorporate those changes in this driver and give it a more generic name..