Bluetooth: btusb: Add support USB ALT 3 for WBS

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 <[email protected]> Signed-off-by: Marcel Holtmann <[email protected]>
vieko · Jun 26, 2021 · e848dbd · e848dbd
1 parent de895b4
commit e848dbd
Showing 1 changed file with 7 additions and 0 deletions.
diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
@@ -1756,6 +1756,13 @@ 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)