MAYA W2 module Bluetooth Timeout issue

[pratham_malaviya]

Hi there,

We are trying to bring up the IW612 based Wifi bluetooth module from MAYA with IMX8MP based board.

We were successfully able to bring-up the Wi-Fi we are having issues with bluetooth.

While the Bluetooth functionality works correctly when RTS/CTS flow control is not used, I encounter issues when enabling RTS/CTS.

Specifically, when I connect the RTS and CTS pins between the host and the module, Bluetooth initialization fails with opcode timeouts and TX errors. 

root@verdin-imx8mp-15460290:~# modprobe btnxpuart                                                   
[   42.127549] wlan: SCAN COMPLETED: scanned AP count=17
root@verdin-imx8mp-15460290:~# [   42.439851] Bluetooth: BNEP (Ethernet Emulation) ver 1.3
[   42.445247] Bluetooth: BNEP socket layer initialized
[   43.266730] Bluetooth: hci0: FW already running.
[   45.315028] Bluetooth: hci0: Opcode 0x0c03 failed: -110
[   47.330733] Bluetooth: hci0: Setting baudrate failed (-110)
root@verdin-imx8mp-15460290:~# 
root@verdin-imx8mp-15460290:~# [   49.346732] Bluetooth: hci0: Setting wake-up method failed (-110)
[   51.362750] Bluetooth: hci0: Setting Power Save mode failed (-110)

 Interestingly, if I ground the CTS pin on the Bluetooth module and leave the RTS pin unconnected, the module initializes correctly and basic functionality appears to work. However, when I attempt to scan for nearby Bluetooth devices, the following errors occur:

root@verdin-imx8mp-15460290:~# hciconfig 
hci0:   Type: Primary  Bus: UART
        BD Address: 20:BA:36:56:BB:E0  ACL MTU: 1021:7  SCO MTU: 120:6
        UP RUNNING PSCAN 
        RX bytes:902 acl:0 sco:0 events:65 errors:0
        TX bytes:1610 acl:0 sco:0 commands:64 errors:0
root@verdin-imx8mp-15460290:~# bluetoothctl 
hci0 new_settings: powered bondable ssp br/edr le secure-conn cis-central cis-p
Agent registered
[CHG] Controller 20:BA:36:56:BB:E0 Pairable: yes
[bluetooth]# power on
Changing power on succeeded
[bluetooth]# default-agent
Default agent request successful
[bluetooth]# pairable on
Changing pairable on succeeded
[bluetooth]# scan on
SetDiscoveryFilter success
hci0 type 7 discovering on
Discovery started
[CHG] Controller 20:BA:36:56:BB:E0 Discovering: yes
[bluetooth]# [  139.054737] Bluetooth: hci0: Frame reassembly failed (-84)
[NEW] Device 44:A1:70:C1:74:43 44-A1-70-C1-74-43
[bluetooth]# [  139.836671] Bluetooth: hci0: Frame reassembly failed (-84)
[  139.842218] Bluetooth: hci0: Frame reassembly failed (-84)
[CHG] Device 4F:03:41:6A:A2:92 RSSI: 0xffffffaa (-86)
[bluetooth]# [  139.985060] Bluetooth: hci0: Frame reassembly failed (-84)
[NEW] Device 36:D2:3A:FC:99:05 36-D2-3A-FC-99-05
[bluetooth]# [  140.125421] Bluetooth: hci0: Frame reassembly failed (-84)
[  140.167024] Bluetooth: hci0: Frame reassembly failed (-84)
[  140.177003] Bluetooth: hci0: Frame reassembly failed (-84)

My DTS node looks like this:

&uart1 {
         pinctrl-names = "default";
         pinctrl-0 = <&pinctrl_uart1>;
        status = "okay"; 
        assigned-clocks = <&clk IMX8MP_CLK_UART1>;
        assigned-clock-parents = <&clk IMX8MP_SYS_PLL1_80M>;
        uart-has-rtscts;
       bluetooth {
              compatible = "nxp,88w8987-bt";
             fw-init-baudrate = <115200>;
             status = "okay";
       };
};
 &iomuxc {
 pinctrl_uart1: uart1grp {
         fsl,pins =
                 <MX8MP_IOMUXC_SAI2_RXD0__UART1_DCE_RTS          0x1c4>, /* SODIMM 135 */
                 <MX8MP_IOMUXC_SAI2_TXFS__UART1_DCE_CTS          0x1c4>, /* SODIMM 133 */
                 <MX8MP_IOMUXC_UART1_RXD__UART1_DCE_RX           0x1c4>, /* SODIMM 129 */
                 <MX8MP_IOMUXC_UART1_TXD__UART1_DCE_TX           0x1c4>; /* SODIMM 131 */
 };
};

My hardware connection are as follows:

HOST SIDE (IMX8MP) MODULE SIDE (MAYA W2)

UART1_TX	UART_RX
UART1_RX	UART_TX
UART1_CTS	UART_RTS
UART1_RTS	UART_CTS

I have also tried reversing the RTS and CTS connections, but there was no change in behaviour.

1. What could be causing this failure when RTS/CTS is enabled?
2. What configuration or hardware checks would you recommend to ensure proper RTS/CTS operation?

[Chavira]

HI @pratham_malaviya!

Thank you for contacting NXP Support!

What BSP version are you using?

Can you try using the next values?

 pinctrl_uart1: uart1grp {
         fsl,pins =
                 <MX8MP_IOMUXC_SAI2_RXD0__UART1_DCE_RTS          0x140>, /* SODIMM 135 */
                 <MX8MP_IOMUXC_SAI2_TXFS__UART1_DCE_CTS          0x140>, /* SODIMM 133 */
                 <MX8MP_IOMUXC_UART1_RXD__UART1_DCE_RX           0x140>, /* SODIMM 129 */
                 <MX8MP_IOMUXC_UART1_TXD__UART1_DCE_TX           0x140>; /* SODIMM 131 */
 };

Remember that you have to install the wifi (modprobe moal mod_para=nxp/wifi_mod_para.conf) drivers before to insert the btnxpuart module.

Best Regards!

Chavira

[pratham_malaviya]

Hi @Chavira ,

Thanks for your response,

What BSP version are you using?

--I am using linux kernel version 6.6.74.

Can you try using the next values?

-- I have tried this but i am having the same OP code failure error.

Error log:

root@verdin-imx8mp-15460290:~# modprobe btnxpuart
[   38.966015] wlan: SCAN COMPLETED: scanned AP count=8
[   38.980544] wlan: mlan0 START SCAN
root@verdin-imx8mp-15460290:~# [   40.376824] Bluetooth: BNEP (Ethernet Emulation) ver 1.3
[   40.382218] Bluetooth: BNEP socket layer initialized
[   41.186982] Bluetooth: hci0: FW already running.
[   43.234989] Bluetooth: hci0: Opcode 0x0c03 failed: -110
[   44.843967] wlan: SCAN COMPLETED: scanned AP count=12
[   45.250972] Bluetooth: hci0: Setting baudrate failed (-110)
[   47.267007] Bluetooth: hci0: Setting wake-up method failed (-110)
[   49.282970] Bluetooth: hci0: Setting Power Save mode failed (-110)

[DanielRuvalcaba]

Hi,

The NXP Bluetooth Serial driver can run standalone, so it is OK to only issue modprobe btnxpuart.

1. I assume you are using a custom board based on the iMX8MP, can you confirm?
2. Could you please try with fw-init-baudrate=3000000 (just because this is the one I tried)?
4. Are you able to see with an external device like a logic analyzer the RTS and CTS communication?
5. I did a test on my side using the iMX8MP-EVK and the 2EL module, and it is working on my side. I just changed the default dtb. You can take a look to the one I used in the iMX8MP BSP.

Regards,

Daniel.