Re: [PATCH] Bluetooth: qca: Support downloading board id specific NVM for WCN6855

[Johan Hovold <johan@kernel.org>]

On Wed, Nov 13, 2024 at 10:26:56PM -0800, Zijun Hu wrote:
> Download board id specific NVM instead of default for WCN6855 if board
> id is available, and that is required by Lenovo ThinkPad X13s.
> 
> Cc: Bjorn Andersson <bjorande@quicinc.com>
> Cc: Aiqun Yu (Maria) <quic_aiquny@quicinc.com>
> Cc: Cheng Jiang <quic_chejiang@quicinc.com>
> Cc: Johan Hovold <johan@kernel.org>
> Cc: Jens Glathe <jens.glathe@oldschoolsolutions.biz>
> Cc: Steev Klimaszewski <steev@kali.org>
> Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>

This works like a charm on my X13s which has the GF variant.

Unlike with the "default" NVM file, the range is excellent with the
board-specific file now pushed to linux-firmware (similar to what I see
when using the Windows driver NVM file). Specifically, the range with
the headphones I use for testing increases from about two meters to 20 m
(around a bend).

Even if these NVM files didn't make it into the November release of
linux-firmware and therefore won't make it into the distros for another
month, I think we should mark this one as a fix and backport it to
stable as soon as possible.

Zijun, could you amend the commit message with some details about why
this needs to be fixed and backported (e.g. refer to my range example
above)?

Fixes: 095327fede00 ("Bluetooth: hci_qca: Add support for QTI Bluetooth chip wcn6855")
Cc: stable@vger.kernel.org	# 6.4

It's possible to add a comment after the stable tag to delay backporting
until the next linux-firmware release, but in this case it may be better
to break existing setups and force people to update to the correct radio
calibration data.

Either way:

Reviewed-by: Johan Hovold <johan+linaro@kernel.org>
Tested-by: Johan Hovold <johan+linaro@kernel.org>

Johan