Re: Question about rtl8761b Realtek bluetooth dongle firmware

Re: Question about rtl8761b Realtek bluetooth dongle firmware

[Jeremy MJ]

Hi,

I have reached out to realtek to inquire about licensing and
permissibility of inclusion of the firmware to linux-firmware, will
update if / when I hear back.

This came up with another user on the Mint forums, who has a specific
brand using this chipset which provides beta Linux drivers and
firmware:
https://forums.linuxmint.com/viewtopic.php?f=49&t=319260&e=1

I have tested both the driver and the firmware in linux 5.8; both
appear to mostly work (a couple of unexpected event for opcode errors
with the bluetooth module when using the firmware).

Thank you Zamir for your work on the initial device recognition issue.
Would be nice to have broader support of bt5 dongles in Linux.

Regards,

--
Jeremy MountainJohnson
jskier@gmail.com

----
From: Zamir SUN <sztsian@gmail.com>
To: linux-firmware@kernel.org
Cc: sztsian@gmail.com
Subject: Question about rtl8761b Realtek bluetooth dongle firmware
Date: Fri, 10 Apr 2020 23:44:49 +0800
Message-ID: <4bb6d05c-b6b6-f8c8-3a49-f76cd129c665@gmail.com> (raw)

Hi,

Recently I purchased a unbranded USB Bluetooth dongle which is found not
supported by Linux yet. And the vendor declare it to have rtl8716b chip.
After playing with it for a while we've figured out that it's mostly
compatible with the btrtl driver, with the difference firmware needed.
We found the firmware from the Windows driver CD shipped along with the
dongle and confirmed it works in Linux. I've carefully checked the
Windows driver as well as the installer and did not see any EULA. As I
don't work for Realtek, neither the producer of this USB dongle, so I am
writing to ask if I can submit to linux-firmware?

The patch to the driver is already sent out
https://patchwork.kernel.org/patch/11483367/

Thanks in advance.
-- 
Zamir SUN
Fedora user
GPG : 1D86 6D4A 49CE 4BBD 72CF FCF5 D856 6E11 F2A0 525E

Re: Question about rtl8761b Realtek bluetooth dongle firmware

[Zamir SUN]

On 8/4/20 10:14 PM, Jeremy MJ wrote:
> Hi,
> 
> I have reached out to realtek to inquire about licensing and
> permissibility of inclusion of the firmware to linux-firmware, will
> update if / when I hear back.
> 

Hi Jeremy,

Thanks for the reply. Just fyi, I've ever send email to the latest 
Realtek btrtl submitter of linux-firmware (hildawu@), but I did not get 
any reply till now.

I can share where the firmware stays in the Windows driver, but I'm 
reluctant because I don't know if it is proper to share it publicly. 
Getting confirmation from the Realtek engineers is definitely preferred.

> This came up with another user on the Mint forums, who has a specific
> brand using this chipset which provides beta Linux drivers and
> firmware:
> https://forums.linuxmint.com/viewtopic.php?f=49&t=319260&e=1
> 

Well, I cannot read the thread. Looks like account needed and register 
requires a really complex password.. That said, I will try again to read 
it later.

> I have tested both the driver and the firmware in linux 5.8; both
> appear to mostly work (a couple of unexpected event for opcode errors
> with the bluetooth module when using the firmware).
> 

The driver itself got merged in kernel 5.8. And to be a little verbose, 
I'm not sure if distribution packaging (rpm/deb etc.) will try to detect 
the firmware automatically so I did *not* add a MODULE_FIRMWARE line in 
the patch. That shouldn't affect the user as I can listen to music using 
the 5.8 kernel without any hack to the driver (if copying the firmware 
is not called a hack).

The only error I see is the "command 0x2038 tx timeout". And I do 
realize that there are compatible issues (the adapter + firmware can 
only pare with my newest headset, not the ones that I bought over 3 
years ago). Not sure if it is a driver issue or my userspace problems.

The config error is benign. This do not require a config binary.

[  544.152212] Bluetooth: hci0: RTL: examining hci_ver=0a hci_rev=000b 
lmp_ver=0a lmp_subver=8761
[  544.153186] Bluetooth: hci0: RTL: rom_version status=0 version=1
[  544.153190] Bluetooth: hci0: RTL: loading rtl_bt/rtl8761b_fw.bin
[  544.153337] Bluetooth: hci0: RTL: loading rtl_bt/rtl8761b_config.bin
[  544.153366] bluetooth hci0: Direct firmware load for 
rtl_bt/rtl8761b_config.bin failed with error -2
[  544.153372] Bluetooth: hci0: RTL: cfg_sz -2, total sz 18788
[  544.260240] Bluetooth: hci0: RTL: fw version 0xd898c37c
[  546.382558] Bluetooth: hci0: command 0x2038 tx timeout
[  595.434875] Bluetooth: hci0: Ignoring error of Inquiry Cancel command
[  844.482285] debugfs: File 'force_bredr_smp' in directory 'hci0' 
already present!
[  846.539979] Bluetooth: hci0: command 0x2038 tx timeout


> Thank you Zamir for your work on the initial device recognition issue.
> Would be nice to have broader support of bt5 dongles in Linux.
> 

Thanks again for bringing this up. And let's wish hardware vendors can 
do more good to Linux community in the future.

> Regards,
> 
> --
> Jeremy MountainJohnson
> jskier@gmail.com
> 
> ----
> From: Zamir SUN <sztsian@gmail.com>
> To: linux-firmware@kernel.org
> Cc: sztsian@gmail.com
> Subject: Question about rtl8761b Realtek bluetooth dongle firmware
> Date: Fri, 10 Apr 2020 23:44:49 +0800
> Message-ID: <4bb6d05c-b6b6-f8c8-3a49-f76cd129c665@gmail.com> (raw)
> 
> Hi,
> 
> Recently I purchased a unbranded USB Bluetooth dongle which is found not
> supported by Linux yet. And the vendor declare it to have rtl8716b chip.
> After playing with it for a while we've figured out that it's mostly
> compatible with the btrtl driver, with the difference firmware needed.
> We found the firmware from the Windows driver CD shipped along with the
> dongle and confirmed it works in Linux. I've carefully checked the
> Windows driver as well as the installer and did not see any EULA. As I
> don't work for Realtek, neither the producer of this USB dongle, so I am
> writing to ask if I can submit to linux-firmware?
> 
> The patch to the driver is already sent out
> https://patchwork.kernel.org/patch/11483367/
> 
> Thanks in advance.
> 

-- 
Zamir SUN
Fedora user
GPG : 1D86 6D4A 49CE 4BBD 72CF FCF5 D856 6E11 F2A0 525E

Question about rtl8761b Realtek bluetooth dongle firmware

[Zamir SUN]

Hi,

Recently I purchased a unbranded USB Bluetooth dongle which is found not 
supported by Linux yet. And the vendor declare it to have rtl8716b chip. 
After playing with it for a while we've figured out that it's mostly 
compatible with the btrtl driver, with the difference firmware needed. 
We found the firmware from the Windows driver CD shipped along with the 
dongle and confirmed it works in Linux. I've carefully checked the 
Windows driver as well as the installer and did not see any EULA. As I 
don't work for Realtek, neither the producer of this USB dongle, so I am 
writing to ask if I can submit to linux-firmware?

The patch to the driver is already sent out
https://patchwork.kernel.org/patch/11483367/

Thanks in advance.
-- 
Zamir SUN
Fedora user
GPG : 1D86 6D4A 49CE 4BBD 72CF FCF5 D856 6E11 F2A0 525E