QCA9377 (0x0cf3:e500) detected but Bluetooth fails to come up on USB bus

[Rameshkumar9159]

Hello,

I am using a QCA9377 WiFi + Bluetooth module on the phyBOARD-Polis i.MX8M Mini.

The device is detected correctly:

QCA9377 0x0cf3:e500 Added successfully

Bluetooth firmware loads successfully and the hci0 interface is created.
However, bringing the Bluetooth interface UP fails.

Error observed:

debugfs: File 'dut_mode' in directory 'hci0' already present!
Can't init device hci0: Invalid request code (56)

hciconfig -a output:

hci0: Type: Primary Bus: USB
BD Address: C4:93:00:4B:8A:F6
DOWN

Attempting:

hciconfig hci0 up

Results in:

Can't init device hci0: Invalid request code (56)

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Environment:

Board : phyBOARD-Polis i.MX8M Mini
SoC : i.MX8MM
Module : QCA9377 (0x0cf3:e500)
Kernel : 5.4.70
BSP : L5.4.70-2.3.0
Bus : USB
Firmware : rampatch_usb_00000302.bin && nvm_usb_00000302.bin

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Steps to Reproduce:

1. Boot system
2. Firmware loads
3. hci0 interface created
4. Run: hciconfig hci0 up

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Expected Behavior:

Bluetooth interface should transition to UP state.

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Actual Behavior:

Fails with:

root@phyboard-polis-imx8mm-4:~# hciconfig hci0 up
[ 237.447633] debugfs: File 'dut_mode' in directory 'hci0' already present!
Can't init device hci0: Invalid request code (56)

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Additional Notes:

• Issue does NOT occur on Kernel 5.4.47
• Issue observed on Kernel 5.4.70

Any guidance would be appreciated.

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Best regards,
T S Rameshkumar
rameshkumar.t@phytecembedded.in