* bluetooth hci0: Direct firmware load for rtl_bt/rtl8761a_config.bin failed with error -2
@ 2026-04-29 19:10 Zenm Chen
2026-04-30 2:22 ` Max Chou
0 siblings, 1 reply; 3+ messages in thread
From: Zenm Chen @ 2026-04-29 19:10 UTC (permalink / raw)
To: linux-bluetooth, max.chou, hildawu; +Cc: pkshih
Hi,
Recently I got an RTL8812AEBT card which is a WiFi5 + BT4.0 device.
Bluetooth is working fine but I see the warning below in dmesg. It seems
the config file rtl_bt/rtl8761a_config.bin is missing, not sure if this
should be fixed or not.
$ dmesg
[ 171.900777] Bluetooth: Core ver 2.22
[ 171.900818] NET: Registered PF_BLUETOOTH protocol family
[ 171.900820] Bluetooth: HCI device and connection manager initialized
[ 171.900825] Bluetooth: HCI socket layer initialized
[ 171.900827] Bluetooth: L2CAP socket layer initialized
[ 171.900831] Bluetooth: SCO socket layer initialized
[ 171.934237] usbcore: registered new interface driver btusb
[ 171.941534] Bluetooth: hci0: RTL: examining hci_ver=06 hci_rev=000a lmp_ver=06 lmp_subver=8761
[ 171.943635] Bluetooth: hci0: RTL: rom_version status=0 version=3
[ 171.945657] Bluetooth: hci0: RTL: btrtl_initialize: key id 0
[ 171.945664] Bluetooth: hci0: RTL: loading rtl_bt/rtl8761a_fw.bin
[ 171.949630] Bluetooth: hci0: RTL: loading rtl_bt/rtl8761a_config.bin
[ 171.949697] bluetooth hci0: Direct firmware load for rtl_bt/rtl8761a_config.bin failed with error -2
[ 171.949712] Bluetooth: hci0: RTL: cfg_sz -2, total sz 22640
[ 172.020303] Bluetooth: BNEP (Ethernet Emulation) ver 1.3
[ 172.020309] Bluetooth: BNEP filters: protocol multicast
[ 172.020314] Bluetooth: BNEP socket layer initialized
[ 172.524780] Bluetooth: hci0: RTL: fw version 0x0e3e4380
[ 172.664330] Bluetooth: MGMT ver 1.22
[ 172.683252] NET: Registered PF_ALG protocol family
[ 172.744110] Bluetooth: RFCOMM TTY layer initialized
[ 172.744124] Bluetooth: RFCOMM socket layer initialized
[ 172.744136] Bluetooth: RFCOMM ver 1.11
$ sudo lsusb -v -d 0bda:b761
Bus 003 Device 004: ID 0bda:b761 Realtek Semiconductor Corp. Bluetooth Radio
Negotiated speed: Full Speed (12Mbps)
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.10
bDeviceClass 224 Wireless
bDeviceSubClass 1 Radio Frequency
bDeviceProtocol 1 Bluetooth
bMaxPacketSize0 64
idVendor 0x0bda Realtek Semiconductor Corp.
idProduct 0xb761 Bluetooth Radio
bcdDevice 2.00
iManufacturer 1 Realtek
iProduct 2 Bluetooth Radio
iSerial 3 00e04c000001
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 0x00b1
bNumInterfaces 2
bConfigurationValue 1
iConfiguration 0
bmAttributes 0xe0
Self Powered
Remote Wakeup
MaxPower 500mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 3
bInterfaceClass 224 Wireless
bInterfaceSubClass 1 Radio Frequency
bInterfaceProtocol 1 Bluetooth
iInterface 4 Bluetooth Radio
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0010 1x 16 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 0
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 0
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 224 Wireless
bInterfaceSubClass 1 Radio Frequency
bInterfaceProtocol 1 Bluetooth
iInterface 4 Bluetooth Radio
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 4 Bluetooth Radio
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 4 Bluetooth Radio
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 4 Bluetooth Radio
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 4 Bluetooth Radio
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 4 Bluetooth Radio
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
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 0x00000002
HIRD Link Power Management (LPM) Supported
Device Status: 0x0001
Self Powered
$ sudo cat /sys/kernel/debug/usb/devices
T: Bus=03 Lev=01 Prnt=01 Port=04 Cnt=03 Dev#= 4 Spd=12 MxCh= 0
D: Ver= 2.10 Cls=e0(wlcon) Sub=01 Prot=01 MxPS=64 #Cfgs= 1
P: Vendor=0bda ProdID=b761 Rev= 2.00
S: Manufacturer=Realtek
S: Product=Bluetooth Radio
S: SerialNumber=00e04c000001
C:* #Ifs= 2 Cfg#= 1 Atr=e0 MxPwr=500mA
I:* If#= 0 Alt= 0 #EPs= 3 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E: Ad=81(I) Atr=03(Int.) MxPS= 16 Ivl=1ms
E: Ad=02(O) Atr=02(Bulk) MxPS= 64 Ivl=0ms
E: Ad=82(I) Atr=02(Bulk) MxPS= 64 Ivl=0ms
I:* If#= 1 Alt= 0 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E: Ad=03(O) Atr=01(Isoc) MxPS= 0 Ivl=1ms
E: Ad=83(I) Atr=01(Isoc) MxPS= 0 Ivl=1ms
I: If#= 1 Alt= 1 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E: Ad=03(O) Atr=01(Isoc) MxPS= 9 Ivl=1ms
E: Ad=83(I) Atr=01(Isoc) MxPS= 9 Ivl=1ms
I: If#= 1 Alt= 2 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E: Ad=03(O) Atr=01(Isoc) MxPS= 17 Ivl=1ms
E: Ad=83(I) Atr=01(Isoc) MxPS= 17 Ivl=1ms
I: If#= 1 Alt= 3 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E: Ad=03(O) Atr=01(Isoc) MxPS= 25 Ivl=1ms
E: Ad=83(I) Atr=01(Isoc) MxPS= 25 Ivl=1ms
I: If#= 1 Alt= 4 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E: Ad=03(O) Atr=01(Isoc) MxPS= 33 Ivl=1ms
E: Ad=83(I) Atr=01(Isoc) MxPS= 33 Ivl=1ms
I: If#= 1 Alt= 5 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E: Ad=03(O) Atr=01(Isoc) MxPS= 49 Ivl=1ms
E: Ad=83(I) Atr=01(Isoc) MxPS= 49 Ivl=1ms
^ permalink raw reply [flat|nested] 3+ messages in thread
* RE: bluetooth hci0: Direct firmware load for rtl_bt/rtl8761a_config.bin failed with error -2
2026-04-29 19:10 bluetooth hci0: Direct firmware load for rtl_bt/rtl8761a_config.bin failed with error -2 Zenm Chen
@ 2026-04-30 2:22 ` Max Chou
2026-05-05 7:25 ` Zenm Chen
0 siblings, 1 reply; 3+ messages in thread
From: Max Chou @ 2026-04-30 2:22 UTC (permalink / raw)
To: Zenm Chen, linux-bluetooth@vger.kernel.org, Hilda Wu; +Cc: Ping-Ke Shih
Hi!
The config file rtl8761a_config is not mandatory. In ic_id_table[],
.config_needed is indeed set to false. Please rest assured regarding
this matter.
If you would like to fix the warning message, it would be good to
send a patch to add rtl8761a_config.bin containing only the header
to the linux-firmware repository.
BRs,
Max
> -----Original Message-----
> From: Zenm Chen <zenmchen@gmail.com>
> Sent: Thursday, April 30, 2026 3:10 AM
> To: linux-bluetooth@vger.kernel.org; Max Chou <max.chou@realtek.com>;
> Hilda Wu <hildawu@realtek.com>
> Cc: Ping-Ke Shih <pkshih@realtek.com>
> Subject: bluetooth hci0: Direct firmware load for rtl_bt/rtl8761a_config.bin
> failed with error -2
>
>
> External mail : This email originated from outside the organization. Do not
> reply, click links, or open attachments unless you recognize the sender and
> know the content is safe.
>
>
>
> Hi,
>
> Recently I got an RTL8812AEBT card which is a WiFi5 + BT4.0 device.
> Bluetooth is working fine but I see the warning below in dmesg. It seems the
> config file rtl_bt/rtl8761a_config.bin is missing, not sure if this should be
> fixed or not.
>
> $ dmesg
> [ 171.900777] Bluetooth: Core ver 2.22
> [ 171.900818] NET: Registered PF_BLUETOOTH protocol family
> [ 171.900820] Bluetooth: HCI device and connection manager initialized
> [ 171.900825] Bluetooth: HCI socket layer initialized [ 171.900827]
> Bluetooth: L2CAP socket layer initialized [ 171.900831] Bluetooth: SCO
> socket layer initialized [ 171.934237] usbcore: registered new interface
> driver btusb [ 171.941534] Bluetooth: hci0: RTL: examining hci_ver=06
> hci_rev=000a lmp_ver=06 lmp_subver=8761 [ 171.943635] Bluetooth: hci0:
> RTL: rom_version status=0 version=3 [ 171.945657] Bluetooth: hci0: RTL:
> btrtl_initialize: key id 0 [ 171.945664] Bluetooth: hci0: RTL: loading
> rtl_bt/rtl8761a_fw.bin [ 171.949630] Bluetooth: hci0: RTL: loading
> rtl_bt/rtl8761a_config.bin [ 171.949697] bluetooth hci0: Direct firmware
> load for rtl_bt/rtl8761a_config.bin failed with error -2 [ 171.949712]
> Bluetooth: hci0: RTL: cfg_sz -2, total sz 22640 [ 172.020303] Bluetooth:
> BNEP (Ethernet Emulation) ver 1.3 [ 172.020309] Bluetooth: BNEP filters:
> protocol multicast [ 172.020314] Bluetooth: BNEP socket layer initialized
> [ 172.524780] Bluetooth: hci0: RTL: fw version 0x0e3e4380 [ 172.664330]
> Bluetooth: MGMT ver 1.22 [ 172.683252] NET: Registered PF_ALG protocol
> family [ 172.744110] Bluetooth: RFCOMM TTY layer initialized
> [ 172.744124] Bluetooth: RFCOMM socket layer initialized [ 172.744136]
> Bluetooth: RFCOMM ver 1.11
>
> $ sudo lsusb -v -d 0bda:b761
> Bus 003 Device 004: ID 0bda:b761 Realtek Semiconductor Corp. Bluetooth
> Radio Negotiated speed: Full Speed (12Mbps) Device Descriptor:
> bLength 18
> bDescriptorType 1
> bcdUSB 2.10
> bDeviceClass 224 Wireless
> bDeviceSubClass 1 Radio Frequency
> bDeviceProtocol 1 Bluetooth
> bMaxPacketSize0 64
> idVendor 0x0bda Realtek Semiconductor Corp.
> idProduct 0xb761 Bluetooth Radio
> bcdDevice 2.00
> iManufacturer 1 Realtek
> iProduct 2 Bluetooth Radio
> iSerial 3 00e04c000001
> bNumConfigurations 1
> Configuration Descriptor:
> bLength 9
> bDescriptorType 2
> wTotalLength 0x00b1
> bNumInterfaces 2
> bConfigurationValue 1
> iConfiguration 0
> bmAttributes 0xe0
> Self Powered
> Remote Wakeup
> MaxPower 500mA
> Interface Descriptor:
> bLength 9
> bDescriptorType 4
> bInterfaceNumber 0
> bAlternateSetting 0
> bNumEndpoints 3
> bInterfaceClass 224 Wireless
> bInterfaceSubClass 1 Radio Frequency
> bInterfaceProtocol 1 Bluetooth
> iInterface 4 Bluetooth Radio
> Endpoint Descriptor:
> bLength 7
> bDescriptorType 5
> bEndpointAddress 0x81 EP 1 IN
> bmAttributes 3
> Transfer Type Interrupt
> Synch Type None
> Usage Type Data
> wMaxPacketSize 0x0010 1x 16 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 0
> 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 0
> Interface Descriptor:
> bLength 9
> bDescriptorType 4
> bInterfaceNumber 1
> bAlternateSetting 0
> bNumEndpoints 2
> bInterfaceClass 224 Wireless
> bInterfaceSubClass 1 Radio Frequency
> bInterfaceProtocol 1 Bluetooth
> iInterface 4 Bluetooth Radio
> 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 4 Bluetooth Radio
> 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 4 Bluetooth Radio
> 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 4 Bluetooth Radio
> 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 4 Bluetooth Radio
> 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 4 Bluetooth Radio
> 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
> 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 0x00000002
> HIRD Link Power Management (LPM) Supported
> Device Status: 0x0001
> Self Powered
>
> $ sudo cat /sys/kernel/debug/usb/devices
> T: Bus=03 Lev=01 Prnt=01 Port=04 Cnt=03 Dev#= 4 Spd=12 MxCh= 0
> D: Ver= 2.10 Cls=e0(wlcon) Sub=01 Prot=01 MxPS=64 #Cfgs= 1
> P: Vendor=0bda ProdID=b761 Rev= 2.00
> S: Manufacturer=Realtek
> S: Product=Bluetooth Radio
> S: SerialNumber=00e04c000001
> C:* #Ifs= 2 Cfg#= 1 Atr=e0 MxPwr=500mA
> I:* If#= 0 Alt= 0 #EPs= 3 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
> E: Ad=81(I) Atr=03(Int.) MxPS= 16 Ivl=1ms
> E: Ad=02(O) Atr=02(Bulk) MxPS= 64 Ivl=0ms
> E: Ad=82(I) Atr=02(Bulk) MxPS= 64 Ivl=0ms
> I:* If#= 1 Alt= 0 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
> E: Ad=03(O) Atr=01(Isoc) MxPS= 0 Ivl=1ms
> E: Ad=83(I) Atr=01(Isoc) MxPS= 0 Ivl=1ms
> I: If#= 1 Alt= 1 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
> E: Ad=03(O) Atr=01(Isoc) MxPS= 9 Ivl=1ms
> E: Ad=83(I) Atr=01(Isoc) MxPS= 9 Ivl=1ms
> I: If#= 1 Alt= 2 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
> E: Ad=03(O) Atr=01(Isoc) MxPS= 17 Ivl=1ms
> E: Ad=83(I) Atr=01(Isoc) MxPS= 17 Ivl=1ms
> I: If#= 1 Alt= 3 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
> E: Ad=03(O) Atr=01(Isoc) MxPS= 25 Ivl=1ms
> E: Ad=83(I) Atr=01(Isoc) MxPS= 25 Ivl=1ms
> I: If#= 1 Alt= 4 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
> E: Ad=03(O) Atr=01(Isoc) MxPS= 33 Ivl=1ms
> E: Ad=83(I) Atr=01(Isoc) MxPS= 33 Ivl=1ms
> I: If#= 1 Alt= 5 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
> E: Ad=03(O) Atr=01(Isoc) MxPS= 49 Ivl=1ms
> E: Ad=83(I) Atr=01(Isoc) MxPS= 49 Ivl=1ms
^ permalink raw reply [flat|nested] 3+ messages in thread
* RE: bluetooth hci0: Direct firmware load for rtl_bt/rtl8761a_config.bin failed with error -2
2026-04-30 2:22 ` Max Chou
@ 2026-05-05 7:25 ` Zenm Chen
0 siblings, 0 replies; 3+ messages in thread
From: Zenm Chen @ 2026-05-05 7:25 UTC (permalink / raw)
To: max.chou; +Cc: hildawu, linux-bluetooth, pkshih, zenmchen
Max Chou <max.chou@realtek.com> 於 2026年4月30日週四 上午10:22寫道：
>
> Hi!
> The config file rtl8761a_config is not mandatory. In ic_id_table[],
> .config_needed is indeed set to false. Please rest assured regarding
> this matter.
> If you would like to fix the warning message, it would be good to
> send a patch to add rtl8761a_config.bin containing only the header
> to the linux-firmware repository.
>
> BRs,
> Max
>
Hi Max,
Thank you for the clarification! After adding an empty config file,
Bluetooth is working as usual and the error message doesn't appear anymore.
$ od -t x1 /lib/firmware/rtl_bt/rtl8761bu_config.bin
0000000 55 ab 23 87 00 00
0000006
$ ls /lib/firmware/rtl_bt/rtl8761{a,bu}_config.bin
lrwxrwxrwx 1 root root 20 Apr 30 22:24 /lib/firmware/rtl_bt/rtl8761a_config.bin -> rtl8761bu_config.bin
-rw-r--r-- 1 root root 6 Mar 5 01:40 /lib/firmware/rtl_bt/rtl8761bu_config.bin
$ dmesg
[ 550.038863] Bluetooth: Core ver 2.22
[ 550.038897] NET: Registered PF_BLUETOOTH protocol family
[ 550.038899] Bluetooth: HCI device and connection manager initialized
[ 550.038904] Bluetooth: HCI socket layer initialized
[ 550.038906] Bluetooth: L2CAP socket layer initialized
[ 550.038910] Bluetooth: SCO socket layer initialized
[ 550.070541] usbcore: registered new interface driver btusb
[ 550.077485] Bluetooth: hci0: RTL: examining hci_ver=06 hci_rev=000a lmp_ver=06 lmp_subver=8761
[ 550.079510] Bluetooth: hci0: RTL: rom_version status=0 version=3
[ 550.081469] Bluetooth: hci0: RTL: btrtl_initialize: key id 0
[ 550.081475] Bluetooth: hci0: RTL: loading rtl_bt/rtl8761a_fw.bin
[ 550.083538] Bluetooth: hci0: RTL: loading rtl_bt/rtl8761a_config.bin
[ 550.083853] Bluetooth: hci0: RTL: cfg_sz 6, total sz 22646
[ 550.167668] Bluetooth: BNEP (Ethernet Emulation) ver 1.3
[ 550.167674] Bluetooth: BNEP filters: protocol multicast
[ 550.167679] Bluetooth: BNEP socket layer initialized
[ 550.659710] Bluetooth: hci0: RTL: fw version 0x0e3e4380
[ 550.800287] Bluetooth: MGMT ver 1.22
[ 550.819174] NET: Registered PF_ALG protocol family
[ 550.857408] Bluetooth: RFCOMM TTY layer initialized
[ 550.857422] Bluetooth: RFCOMM socket layer initialized
[ 550.857433] Bluetooth: RFCOMM ver 1.11
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2026-05-05 7:25 UTC | newest]
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2026-04-29 19:10 bluetooth hci0: Direct firmware load for rtl_bt/rtl8761a_config.bin failed with error -2 Zenm Chen
2026-04-30 2:22 ` Max Chou
2026-05-05 7:25 ` Zenm Chen
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