I am getting the same issue with a new device. Everything works fine on one BT USB, but the intel one fails. It is a PCIe card with Intel AX200 Wifi+BT, with BT being passed through a USB header. First boot with new card (dmesg): ``` [ 20.708957] Bluetooth: Core ver 2.22 [ 20.708971] Bluetooth: HCI device and connection manager initialized [ 20.708974] Bluetooth: HCI socket layer initialized [ 20.708975] Bluetooth: L2CAP socket layer initialized [ 20.708978] Bluetooth: SCO socket layer initialized [ 20.718527] usbcore: registered new interface driver btusb [ 20.719034] Bluetooth: hci0: Bootloader revision 0.3 build 0 week 24 2017 [ 20.720327] Bluetooth: hci0: Device revision is 1 [ 20.720328] Bluetooth: hci0: Secure boot is enabled [ 20.720329] Bluetooth: hci0: OTP lock is enabled [ 20.720329] Bluetooth: hci0: API lock is enabled [ 20.720330] Bluetooth: hci0: Debug lock is disabled [ 20.720331] Bluetooth: hci0: Minimum firmware build 1 week 10 2014 [ 20.725091] Bluetooth: hci0: Found device firmware: intel/ibt-20-1-3.sfi [ 21.839173] Bluetooth: BNEP (Ethernet Emulation) ver 1.3 [ 21.839174] Bluetooth: BNEP filters: protocol multicast [ 21.839176] Bluetooth: BNEP socket layer initialized [ 22.274234] Bluetooth: hci0: Waiting for firmware download to complete [ 22.275022] Bluetooth: hci0: Firmware loaded in 1519998 usecs [ 22.275058] Bluetooth: hci0: Waiting for device to boot [ 22.289027] Bluetooth: hci0: Device booted in 13657 usecs [ 22.289187] Bluetooth: hci0: Found Intel DDC parameters: intel/ibt-20-1-3.ddc [ 22.290032] Bluetooth: hci0: Failed to send Intel_Write_DDC (-22) [ 35.565521] Bluetooth: RFCOMM TTY layer initialized [ 35.565525] Bluetooth: RFCOMM socket layer initialized [ 35.565527] Bluetooth: RFCOMM ver 1.11 ``` Next boot: ``` [ 19.608303] Bluetooth: Core ver 2.22 [ 19.608315] Bluetooth: HCI device and connection manager initialized [ 19.608318] Bluetooth: HCI socket layer initialized [ 19.608319] Bluetooth: L2CAP socket layer initialized [ 19.608321] Bluetooth: SCO socket layer initialized [ 19.616842] usbcore: registered new interface driver btusb [ 19.617945] Bluetooth: hci0: Firmware revision 0.0 build 128 week 11 2020 [ 20.872710] Bluetooth: BNEP (Ethernet Emulation) ver 1.3 [ 20.872711] Bluetooth: BNEP filters: protocol multicast [ 20.872714] Bluetooth: BNEP socket layer initialized [ 34.561042] Bluetooth: RFCOMM TTY layer initialized [ 34.561048] Bluetooth: RFCOMM socket layer initialized [ 34.561050] Bluetooth: RFCOMM ver 1.11 ``` `lsusb -v`: ``` Bus 003 Device 003: ID 8087:0029 Intel Corp. Device Descriptor: bLength 18 bDescriptorType 1 bcdUSB 2.01 bDeviceClass 224 Wireless bDeviceSubClass 1 Radio Frequency bDeviceProtocol 1 Bluetooth bMaxPacketSize0 64 idVendor 0x8087 Intel Corp. idProduct 0x0029 bcdDevice 0.01 iManufacturer 0 iProduct 0 iSerial 0 bNumConfigurations 1 Configuration Descriptor: bLength 9 bDescriptorType 2 wTotalLength 0x00c8 bNumInterfaces 2 bConfigurationValue 1 iConfiguration 0 bmAttributes 0xe0 Self Powered Remote Wakeup MaxPower 100mA Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 0 bAlternateSetting 0 bNumEndpoints 3 bInterfaceClass 224 Wireless bInterfaceSubClass 1 Radio Frequency bInterfaceProtocol 1 Bluetooth iInterface 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x81 EP 1 IN bmAttributes 3 Transfer Type Interrupt Synch Type None Usage Type Data wMaxPacketSize 0x0040 1x 64 bytes bInterval 1 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x02 EP 2 OUT bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0040 1x 64 bytes bInterval 1 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x82 EP 2 IN bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0040 1x 64 bytes bInterval 1 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 1 bAlternateSetting 0 bNumEndpoints 2 bInterfaceClass 224 Wireless bInterfaceSubClass 1 Radio Frequency bInterfaceProtocol 1 Bluetooth iInterface 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x03 EP 3 OUT bmAttributes 1 Transfer Type Isochronous Synch Type None Usage Type Data wMaxPacketSize 0x0000 1x 0 bytes bInterval 1 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x83 EP 3 IN bmAttributes 1 Transfer Type Isochronous Synch Type None Usage Type Data wMaxPacketSize 0x0000 1x 0 bytes bInterval 1 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 1 bAlternateSetting 1 bNumEndpoints 2 bInterfaceClass 224 Wireless bInterfaceSubClass 1 Radio Frequency bInterfaceProtocol 1 Bluetooth iInterface 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x03 EP 3 OUT bmAttributes 1 Transfer Type Isochronous Synch Type None Usage Type Data wMaxPacketSize 0x0009 1x 9 bytes bInterval 1 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x83 EP 3 IN bmAttributes 1 Transfer Type Isochronous Synch Type None Usage Type Data wMaxPacketSize 0x0009 1x 9 bytes bInterval 1 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 1 bAlternateSetting 2 bNumEndpoints 2 bInterfaceClass 224 Wireless bInterfaceSubClass 1 Radio Frequency bInterfaceProtocol 1 Bluetooth iInterface 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x03 EP 3 OUT bmAttributes 1 Transfer Type Isochronous Synch Type None Usage Type Data wMaxPacketSize 0x0011 1x 17 bytes bInterval 1 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x83 EP 3 IN bmAttributes 1 Transfer Type Isochronous Synch Type None Usage Type Data wMaxPacketSize 0x0011 1x 17 bytes bInterval 1 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 1 bAlternateSetting 3 bNumEndpoints 2 bInterfaceClass 224 Wireless bInterfaceSubClass 1 Radio Frequency bInterfaceProtocol 1 Bluetooth iInterface 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x03 EP 3 OUT bmAttributes 1 Transfer Type Isochronous Synch Type None Usage Type Data wMaxPacketSize 0x0019 1x 25 bytes bInterval 1 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x83 EP 3 IN bmAttributes 1 Transfer Type Isochronous Synch Type None Usage Type Data wMaxPacketSize 0x0019 1x 25 bytes bInterval 1 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 1 bAlternateSetting 4 bNumEndpoints 2 bInterfaceClass 224 Wireless bInterfaceSubClass 1 Radio Frequency bInterfaceProtocol 1 Bluetooth iInterface 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x03 EP 3 OUT bmAttributes 1 Transfer Type Isochronous Synch Type None Usage Type Data wMaxPacketSize 0x0021 1x 33 bytes bInterval 1 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x83 EP 3 IN bmAttributes 1 Transfer Type Isochronous Synch Type None Usage Type Data wMaxPacketSize 0x0021 1x 33 bytes bInterval 1 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 1 bAlternateSetting 5 bNumEndpoints 2 bInterfaceClass 224 Wireless bInterfaceSubClass 1 Radio Frequency bInterfaceProtocol 1 Bluetooth iInterface 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x03 EP 3 OUT bmAttributes 1 Transfer Type Isochronous Synch Type None Usage Type Data wMaxPacketSize 0x0031 1x 49 bytes bInterval 1 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x83 EP 3 IN bmAttributes 1 Transfer Type Isochronous Synch Type None Usage Type Data wMaxPacketSize 0x0031 1x 49 bytes bInterval 1 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 1 bAlternateSetting 6 bNumEndpoints 2 bInterfaceClass 224 Wireless bInterfaceSubClass 1 Radio Frequency bInterfaceProtocol 1 Bluetooth iInterface 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x03 EP 3 OUT bmAttributes 1 Transfer Type Isochronous Synch Type None Usage Type Data wMaxPacketSize 0x003f 1x 63 bytes bInterval 1 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x83 EP 3 IN bmAttributes 1 Transfer Type Isochronous Synch Type None Usage Type Data wMaxPacketSize 0x003f 1x 63 bytes bInterval 1 Binary Object Store Descriptor: bLength 5 bDescriptorType 15 wTotalLength 0x000c bNumDeviceCaps 1 USB 2.0 Extension Device Capability: bLength 7 bDescriptorType 16 bDevCapabilityType 2 bmAttributes 0x0000040e BESL Link Power Management (LPM) Supported BESL value 1024 us can't get debug descriptor: Resource temporarily unavailable Device Status: 0x0001 Self Powered ```