-
HFP Audio Connection SCO configuration is negotiated symmetrically in both directions, and USB HCI SCO packet framing is also symmetric in both directions. This means that packet size will be the same for reads and writes over HFP SCO socket. HFP profile specification states that valid speech data shall exist on the Synchronous Connection in both directions after the Audio Connection is established. This guarantees that an incoming packet will arrive shortly after SCO connection is established. Use it's size to fix write MTU in case kernel value is wrong. Discussion here https://lore.kernel.org/patchwork/patch/1303411/ Part-of: <pulseaudio/pulseaudio!507>
62776cc8