This is a note to let you know that I've just added the patch titled Bluetooth: btusb: Add support USB ALT 3 for WBS to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: bluetooth-btusb-add-support-usb-alt-3-for-wbs.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 38bb497594f943ab48c933546219f5c69eee47d2 Author: Hilda Wu <hildawu@xxxxxxxxxxx> Date: Fri May 14 11:19:01 2021 +0800 Bluetooth: btusb: Add support USB ALT 3 for WBS [ Upstream commit e848dbd364aca44c9d23c04bef964fab79e2b34f ] Because mSBC frames do not need to be aligned to the SCO packet boundary. Using USB ALT 3 let HCI payload >= 60 bytes, let mSBC data satisfy 60 Bytes avoid payload unaligned situation and fixed some headset no voise issue. USB Alt 3 supported also need HFP support transparent MTU in 72 Bytes. Signed-off-by: Hilda Wu <hildawu@xxxxxxxxxxx> Signed-off-by: Marcel Holtmann <marcel@xxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c index 8f38a2a7da8c..b3c63e06838d 100644 --- a/drivers/bluetooth/btusb.c +++ b/drivers/bluetooth/btusb.c @@ -1721,6 +1721,13 @@ static void btusb_work(struct work_struct *work) * which work with WBS at all. */ new_alts = btusb_find_altsetting(data, 6) ? 6 : 1; + /* Because mSBC frames do not need to be aligned to the + * SCO packet boundary. If support the Alt 3, use the + * Alt 3 for HCI payload >= 60 Bytes let air packet + * data satisfy 60 bytes. + */ + if (new_alts == 1 && btusb_find_altsetting(data, 3)) + new_alts = 3; } if (btusb_switch_alt_setting(hdev, new_alts) < 0)