Kernel should provide the correct mtu/packet size to use for SCO socket
I/O, but it does not currently appear to (as of linux 5.9), see
https://lore.kernel.org/linux-bluetooth/20201210003528.3pmaxvubiwegxmhl@pali/T/
When using mSBC, instead of using the (incorrect) kernel-provided value,
hardcode mtu to 24, corresponding to ALT1 mode. BT-UART adapters should
not require specific mtu, and it appears most BT-USB adapters only
support ALT1, see
https://lore.kernel.org/linux-bluetooth/20201210012003.133000-1-tpiepho@gmail.com/
This code needs to be revised when the issue is sorted out on the kernel
side.
Add setting bluez5.msbc-force-mtu for easier debugging in special cases.
Leave read_mtu as the detected value --- it does not seem to affect
whether BT-USB can record, but Raspberry Pi BT-UART fails to record if a
different value is used.
oFono tries to use the best codec when setting up the audio connection, so
the codec to use is known during call to `acquire` function, after the
transport has been created.
To get the codec before creating the transport, an audio connection is
set-up and discarded during `ofono_audio_card_found()`. It should return
the best codec available, which should not change during the time the
remote is connected.
mSBC can be enabled by passing "bluez5.msbc-support=true" parameter to
pipewire-media-session.
mSBC is automatically selected if remote device supports it.
This tool detects and fixes common English spelling mistakes, with
generally very few mistakes.
Here is the command I used to generate this commit. There were a few
changes that had to be done manually, and of course adding the ignore
file:
```shell
codespell -I .codespell-ignore -x .codespell-ignore -w
```
I didn’t add it to the CI, but this would be a good place for it.
Filter callback should return DBUS_HANDLER_RESULT_HANDLED only when signals
was handled, otherwise it prevents signals to be seen by other objects.
Also fix a Typo.
