Re: [PATCH] Revert "Bluetooth: hci_qca: Set BDA quirk bit if fwnode exists in DT"

[Luiz Augusto von Dentz <luiz.dentz@gmail.com>]

Hi Johan,

On Mon, Mar 25, 2024 at 9:57 AM Linux regression tracking (Thorsten
Leemhuis) <regressions@leemhuis.info> wrote:
>
> Bluetooth Maintainers, what's...
>
> On 14.03.24 16:07, Johan Hovold wrote:
> > On Thu, Mar 14, 2024 at 10:30:36AM -0400, Luiz Augusto von Dentz wrote:
> >> On Thu, Mar 14, 2024 at 4:44 AM Johan Hovold <johan+linaro@kernel.org> wrote:
> >
> >>> This reverts commit 7dcd3e014aa7faeeaf4047190b22d8a19a0db696.
> >>>
> >>> Qualcomm Bluetooth controllers like WCN6855 do not have persistent
> >>> storage for the Bluetooth address and must therefore start as
> >>> unconfigured to allow the user to set a valid address unless one has
> >>> been provided by the boot firmware in the devicetree.
> >>>
> >>> A recent change snuck into v6.8-rc7 and incorrectly started marking the
> >>> default (non-unique) address as valid. This specifically also breaks the
> >>> Bluetooth setup for some user of the Lenovo ThinkPad X13s.
> >>>
> >>> Note that this is the second time Qualcomm breaks the driver this way
> >>> and that this was fixed last year by commit 6945795bc81a ("Bluetooth:
> >>> fix use-bdaddr-property quirk"), which also has some further details.
> >>>
> >>> Fixes: 7dcd3e014aa7 ("Bluetooth: hci_qca: Set BDA quirk bit if fwnode exists in DT")
> >>> Cc: stable@vger.kernel.org      # 6.8
> >>> Cc: Janaki Ramaiah Thota <quic_janathot@quicinc.com>
> >>> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> >>
> >> Well I guess I will need to start asking for evidence that this works
> >> on regular Linux distros then, because it looks like that is not the
> >> environment Janaki and others Qualcomm folks are testing with.
> >>
> >> What I probably would consider as evidence is bluetoothd logs showing
> >> that the controller has been configured correctly or perhaps there is
> >> a simpler way?
> >
> > Well, in this case we actually want the controller to remain
> > unconfigured (e.g. to avoid having every user of the X13s unknowingly
> > use the same default address).
> >
> > I'm not sure why Qualcomm insists on breaking these quirks, but I guess
> > they just haven't understood why they exist. It's of course convenient
> > to be able to use the default address during development without first
> > having to provide an address, but that's not a valid reason to break the
> > driver.
> >
> > From what I hear the Qualcomm developers only care about Android and I
> > believe they have some out-of-tree hack for retrieving the device
> > address directly from the rootfs.
> >
> > For the X13s, and as I think I've mentioned before, we have been trying
> > to get Qualcomm to tell us how to access the assigned addresses that are
> > stored in some secure world storage so that we can set it directly from
> > the driver. But until we figure that out, users will need to continue
> > setting the address manually.
>
> ...the plan forward here? This to me sounds like a case where a quick
> revert is the right (interim?) solution, but nevertheless nothing
> happened for ~10 days now afaics. Or am I missing something?
>
> Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)
> --
> Everything you wanna know about Linux kernel regression tracking:
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>
> #regzbot poke

I guess the following is the latest version:

https://patchwork.kernel.org/project/bluetooth/list/?series=836664

Or are you working on a v5?

-- 
Luiz Augusto von Dentz