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From: Doug Anderson <dianders@chromium.org>
Date: Thu, 25 Apr 2024 09:05:09 -0700
Message-ID: <CAD=FV=Xztc8iYawafEUHOJ3e9=TrqJ4dgCfw8hC92xL2Dow4vQ@mail.gmail.com>
Subject: Re: [PATCH] Bluetooth: qca: fix wcn3991 device address check
To: Johan Hovold <johan+linaro@kernel.org>
Cc: Marcel Holtmann <marcel@holtmann.org>, Luiz Augusto von Dentz <luiz.dentz@gmail.com>, 
	linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org, 
	stable@vger.kernel.org, Janaki Ramaiah Thota <quic_janathot@quicinc.com>
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Hi,

On Thu, Apr 25, 2024 at 12:56=E2=80=AFAM Johan Hovold <johan+linaro@kernel.=
org> wrote:
>
> Qualcomm Bluetooth controllers may not have been provisioned with a
> valid device address and instead end up using the default address
> 00:00:00:00:5a:ad.
>
> This address is now used to determine if a controller has a valid
> address or if one needs to be provided through devicetree or by user
> space before the controller can be used.
>
> It turns out that the WCN3991 controllers used in Chromium Trogdor
> machines use a different default address, 39:98:00:00:5a:ad, which also
> needs to be marked as invalid so that the correct address is fetched
> from the devicetree.
>
> Qualcomm has unfortunately not yet provided any answers as to whether
> the 39:98 encodes a hardware id and if there are other variants of the
> default address that needs to be handled by the driver.
>
> For now, add the Trogdor WCN3991 default address to the device address
> check to avoid having these controllers start with the default address
> instead of their assigned addresses.
>
> Fixes: 00567f70051a ("Bluetooth: qca: fix invalid device address check")
> Cc: stable@vger.kernel.org      # 6.5
> Cc: Doug Anderson <dianders@chromium.org>
> Cc: Janaki Ramaiah Thota <quic_janathot@quicinc.com>
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---
>  drivers/bluetooth/btqca.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
>
> Luiz and Doug,
>
> As the offending commit is now on its way into 6.9, let's just add the
> default address that the Trogdor machines uses to the address check.
>
> We can always amend this when/if Qualcomm provides some more details,
> or, in the worst case, when users report that they need to re-pair their
> Bluetooth gadgets if there are further variations of the default
> address.

I can confirm that this at least gets my boards using their proper BT
address. While I still wonder if this is the best strategy to go with,
I can agree that this is an expedient fix to land it and works:

Tested-by: Douglas Anderson <dianders@chromium.org>

We can continue discussion in response to your original patch [1] to
figure out if this is going to be our long term strategy or not.

[1] https://lore.kernel.org/r/20240416091509.19995-1-johan+linaro@kernel.or=
g