Re: [PATCH v2 1/1] Bluetooth: btrtl: Add support for RTL8761B

From: Marcel Holtmann <marcel@holtmann.org>
To: Zamir SUN <sztsian@gmail.com>
Cc: Johan Hedberg <johan.hedberg@gmail.com>,
	Bluetooth Kernel Mailing List  <linux-bluetooth@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	icenowy@aosc.io
Subject: Re: [PATCH v2 1/1] Bluetooth: btrtl: Add support for RTL8761B
Date: Sat, 11 Apr 2020 07:56:37 +0200	[thread overview]
Message-ID: <3E2F3893-FA3E-4C58-AD0C-879C7A3DD30E@holtmann.org> (raw)
In-Reply-To: <bb48d88a-3b4f-dfa6-bbed-777a76d072ed@gmail.com>

Hi Zamir,

>>> Add new compatible device RTL8761B.
>>> 
>>> Signed-off-by: Ziqian SUN (Zamir) <sztsian@gmail.com>
>>> ---
>>> drivers/bluetooth/btrtl.c | 10 +++++++++-
>>> 1 file changed, 9 insertions(+), 1 deletion(-)
>> can you also please include the content of /sys/kernel/debug/usb/devices for this device in the commit message.
>> And if you run btmon before plugging it in, I like to see what LE Features of Bluetooth 5.0 this dongle really offers.
> 
> Hi Marcel,
> 
> I think you want this section
> 
>        Supported settings: 0x0001bfff
>          Powered
>          Connectable
>          Fast Connectable
>          Discoverable
>          Bondable
>          Link Security
>          Secure Simple Pairing
>          BR/EDR
>          High Speed
>          Low Energy
>          Advertising
>          Secure Connections
>          Debug Keys
>          Privacy
>          Static Address
>          PHY Configuration
> 
> Full log of btmon is available here, with the mac address masked http://fars.ee/Lu85
> 
> I'll send a v3 to include the usb info in the commit message shortly.

This hardware is funny. Before the firmware patching it says this:

< HCI Command: Read Local Version In.. (0x04|0x0001) plen 0
> HCI Event: Command Complete (0x0e) plen 12
      Read Local Version Information (0x04|0x0001) ncmd 2
        Status: Success (0x00)
        HCI version: Bluetooth 5.1 (0x0a) - Revision 11 (0x000b)
        LMP version: Bluetooth 5.1 (0x0a) - Subversion 34657 (0x8761)
        Manufacturer: Realtek Semiconductor Corporation (93)

And after the firmware patching it downgrades to Bluetooth 5.0 standard:

< HCI Command: Read Local Version... (0x04|0x0001) plen 0
> HCI Event: Command Complete (0x0e) plen 12
      Read Local Version Information (0x04|0x0001) ncmd 2
        Status: Success (0x00)
        HCI version: Bluetooth 5.0 (0x09) - Revision 55448 (0xd898)
        LMP version: Bluetooth 5.0 (0x09) - Subversion 50044 (0xc37c)
        Manufacturer: Realtek Semiconductor Corporation (93)

Anyway, I was after these LE Features:

< HCI Command: LE Read Local Suppo.. (0x08|0x0003) plen 0
> HCI Event: Command Complete (0x0e) plen 12
      LE Read Local Supported Features (0x08|0x0003) ncmd 2
        Status: Success (0x00)
        Features: 0xfd 0x5f 0x00 0x00 0x00 0x00 0x00 0x00
          LE Encryption
          Extended Reject Indication
          Slave-initiated Features Exchange
          LE Ping
          LE Data Packet Length Extension
          LL Privacy
          Extended Scanner Filter Policies
          LE 2M PHY
          Stable Modulation Index - Transmitter
          Stable Modulation Index - Receiver
          LE Coded PHY
          LE Extended Advertising
          Channel Selection Algorithm #2

This seems to be a genuine USB dongle with Bluetooth 5.0 features.

Regards

Marcel