Re: [PATCH] Bluetooth: L2CAP: Try harder to accept device not knowing options

On Tue, 2020-12-08 at 10:09 -0800, Luiz Augusto von Dentz wrote:

Hi Bastien,

On Tue, Dec 8, 2020 at 9:36 AM Bastien Nocera [off-list ref]
wrote:

quoted

The current implementation of L2CAP options negotiation will
continue
the negotiation when a device responds with L2CAP_CONF_UNACCEPT
("unaccepted
options"), but not when the device replies with L2CAP_CONF_UNKNOWN
("unknown
options").

Trying to continue the negotiation without ERTM support will allow
Bluetooth-capable XBox One controllers (notably models 1708 and
1797)
to connect.

While the bellow traces looks fine we need to confirm that it doesn't
break the qualification tests e.g:

L2CAP/COS/CFD/BV-14-C [Unknown Mandatory Options Request]

• Test Purpose Verify that the IUT can give the appropriate error
code
when the Lower Tester proposes any number of unknown options where at
least one is mandatory.

Afaik it should be fine to continue with another round of
configuration given that it only expects the error 0x0003, but we
better confirm PTS doesn't expect a L2CAP Disconnect after it.

I tested this today using Fedora's kernel-5.11.0-0.rc2.114.fc34:
https://koji.fedoraproject.org/koji/buildinfo?buildID=1664670
And a local build using the same source kernel with this patch on top.

Both managed to pass the test without any problems.

I'll send the results of the test privately to you and Marcel.

Cheers