Created attachment 289213 [details] dmesg output >Overview: >>My tablet uses AP6255 wifi/bluetooth module with BCM43455 chip. >>The bluetooth controller worked well except bluetooth headset play sound >>glitch.It's not configuration problem in bluez or pulseaudio. >>Some log in dmesg indicated that baud rate was not correctly configured. >>dmesg: >>>Bluetooth: BCM: failed to write clock (-56) >>>Bluetooth: Failed to set baudrate. >Steps to Reproduce: >>1. Power on bluetooth headset. >>2. If it was not automatically connect, connect to headset by bluetoothctl. >>3. play sound. >Actual Results: >>sound glitches. >Expect Results: >>sound well. >Additional Information: >>I suspect the baud rate was too low to transmit audio. >>It seems the chip can't support write clock HCI command. Then bluetooth >>driver used default 115200 baud rate. >>I tried to force configure 4Mbps baud rate to my chip after write clock >>failed, but reset it failed. Then I hardcode baud rate to 3Mbps, it solved >>the glitch problem. >>And I found the commit that introduced the 4Mbsp to ACPI device: >>https://github.com/torvalds/linux/commit/74183a1c50a3c61e62d2e585107ea3c0b942a3ff >>It seems not all ACPI discovered devices can support write clock. >>So maybe the driver should fallback baud rate to 3Mbps if write clock failed. -- Smiles ^__________^ zech