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Subject: Re: Default to HW mSBC on capable controllers ?
From:   Marcel Holtmann <marcel@holtmann.org>
In-Reply-To: <CABBYNZK1kRCvhXnoMbskTYdoFUCOTSAdfUVqv3yftfp_G3NxFA@mail.gmail.com>
Date:   Mon, 28 Dec 2020 13:42:26 +0100
Cc:     =?utf-8?Q?Pali_Roh=C3=A1r?= <pali@kernel.org>,
        Joakim Tjernlund <Joakim.Tjernlund@infinera.com>,
        "linux-bluetooth@vger.kernel.org" <linux-bluetooth@vger.kernel.org>
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To:     Luiz Augusto von Dentz <luiz.dentz@gmail.com>
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Hi Luiz,

>>>>> There seems to be quite a few USB controllers gaining the BTUSB_WIDEBAND_SPEECH which I guess means HW mSBC
>>>> 
>>>> No, it does not mean mSBC.
>>>> 
>>> 
>>> I forgot, if BTUSB_WIDEBAND_SPEECH does not mean capable of HW mSBC, what does it mean?
>> 
>> BTUSB_WIDEBAND_SPEECH flag is just for usb bluetooth adapters. Not for
>> UART or SDIO bluetooth adapters.
>> 
>> It is a hint set for some bluetooth adapters which are on kernel
>> whitelist that wideband speech support is possible for them.
> 
> Actually it is meant indicate to application that BT_PKT_STATUS can be
> used which enables the implementation of PLC (Packet Loss
> Concealment), Ive been advocating to change it or just remove it
> entirely and move it to be queried with BT_PKT_STATUS.

after we fixed the bug with the SCO packet flags, we might not even need this anymore at all and just enable the error reporting unconditionally.

On a side note, I insisted on calling this WIDEBAND_SPEECH option since we should be hiding details behind a single flag and not spread multiple flags for things that need to be combined into one logical feature anyway.

Regards

Marcel