Re: [BUG] Slow bluetooth speed on Apple MacBook Pro 16,1

On Tue, 28 Dec 2021 14:24:09 +1100
"Aditya Garg" [off-list ref] wrote:

The file transfer speed on MacBook Pro 16,1 from an Android device to
Mac is too slow even if I transfer a file of a few Kbs. In case of a
transfer from Mac to my Android device, it simply fails.

Some logs that might be helpful :-

-- Logs begin at Fri 2021-11-26 21:34:04 IST, end at Tue 2021-12-28 08:38:16 IST. --
Dec 28 08:28:29 MacBook kernel: Bluetooth: Core ver 2.22
Dec 28 08:28:29 MacBook kernel: NET: Registered PF_BLUETOOTH protocol family
Dec 28 08:28:29 MacBook kernel: Bluetooth: HCI device and connection manager initialized
Dec 28 08:28:29 MacBook kernel: Bluetooth: HCI socket layer initialized
Dec 28 08:28:29 MacBook kernel: Bluetooth: L2CAP socket layer initialized
Dec 28 08:28:29 MacBook kernel: Bluetooth: SCO socket layer initialized
Dec 28 08:28:29 MacBook kernel: Bluetooth: HCI UART driver ver 2.3
Dec 28 08:28:29 MacBook kernel: Bluetooth: HCI UART protocol H4 registered
Dec 28 08:28:29 MacBook kernel: Bluetooth: HCI UART protocol BCSP registered
Dec 28 08:28:29 MacBook kernel: Bluetooth: HCI UART protocol LL registered
Dec 28 08:28:29 MacBook kernel: Bluetooth: HCI UART protocol ATH3K registered
Dec 28 08:28:29 MacBook kernel: Bluetooth: HCI UART protocol Three-wire (H5) registered
Dec 28 08:28:29 MacBook kernel: Bluetooth: HCI UART protocol Intel registered
Dec 28 08:28:29 MacBook kernel: Bluetooth: HCI UART protocol Broadcom registered
Dec 28 08:28:29 MacBook kernel: Bluetooth: HCI UART protocol QCA registered
Dec 28 08:28:29 MacBook kernel: Bluetooth: HCI UART protocol AG6XX registered
Dec 28 08:28:29 MacBook kernel: Bluetooth: HCI UART protocol Marvell registered
Dec 28 08:28:29 MacBook kernel: Bluetooth: hci0: BCM: failed to write update baudrate (-16)
Dec 28 08:28:29 MacBook kernel: Bluetooth: hci0: Failed to set baudrate

When it fails to set baud rate, btmon has the following:

< HCI Command: Broadcom Update UART Baud Rate (0x3f|0x0018) plen 6 
        Encoded baud rate: Not used (0x0000)
        Explicit baud rate: 3000000 Mbps

HCI Event: Command Complete (0x0e) plen 4                        

      Broadcom Update UART Baud Rate (0x3f|0x0018) ncmd 1
        Status: Command Disallowed (0x0c)

Not sure if this means the command is unsupported by this chip, or if an "Encoded
baud rate" needs to be specified.

Dec 28 08:28:29 MacBook kernel: Bluetooth: hci0: BCM: chip id 150
Dec 28 08:28:29 MacBook kernel: Bluetooth: hci0: BCM: features 0x07
Dec 28 08:28:29 MacBook kernel: Bluetooth: hci0: BCM4364B3 Trinidad Olympic GEN (MFG)
Dec 28 08:28:29 MacBook kernel: Bluetooth: hci0: BCM (001.016.075) build 0099
Dec 28 08:28:29 MacBook kernel: Bluetooth: hci0: BCM: firmware Patch file not found, tried:
Dec 28 08:28:29 MacBook kernel: Bluetooth: hci0: BCM: 'brcm/BCM.hcd'
Dec 28 08:28:40 MacBook kernel: Bluetooth: BNEP (Ethernet Emulation) ver 1.3
Dec 28 08:28:40 MacBook kernel: Bluetooth: BNEP filters: protocol multicast
Dec 28 08:28:40 MacBook kernel: Bluetooth: BNEP socket layer initialized
Dec 28 08:35:02 MacBook kernel: Bluetooth: RFCOMM TTY layer initialized
Dec 28 08:35:02 MacBook kernel: Bluetooth: RFCOMM socket layer initialized
Dec 28 08:35:02 MacBook kernel: Bluetooth: RFCOMM ver 1.11