Re: regression: kernel 6.4.x breaks scanning/pairing (but not use) of LE devices

[Bruno Pitrus <brunopitrus@hotmail.com>]

[Resending this for posterity so that it ends up in the mailing list archives]
Dnia wtorek, 15 sierpnia 2023 01:38:10 CEST piszesz:
> Hi Bruno,
> 
> On Mon, Aug 14, 2023 at 1:21 PM Luiz Augusto von Dentz
> <luiz.dentz@gmail.com> wrote:
> >
> > Hi Bruno,
> >
> > On Mon, Aug 14, 2023 at 3:00 AM Bruno Pitrus <brunopitrus@hotmail.com> wrote:
> > >
> > > Dnia piątek, 11 sierpnia 2023 19:11:50 CEST Luiz Augusto von Dentz pisze:
> > > > Hi Bruno,
> > > >
> > > > On Fri, Aug 11, 2023 at 4:25 AM Bruno Pitrus <brunopitrus@hotmail.com> wrote:
> > > > >
> > > > > Dnia sobota, 5 sierpnia 2023 09:31:08 CEST Paul Menzel pisze:
> > > > > > [Cc: +regressions@]
> > > > > >
> > > > > > #regzbot introduced v6.3.9..v6.4.2
> > > > > >
> > > > > > Dear Bruno,
> > > > > >
> > > > > >
> > > > > > Thank you for your report.
> > > > > >
> > > > > > Am 04.08.23 um 20:55 schrieb Bruno Pitrus:
> > > > > > > I am using openSUSE Tumbleweed on a Dell Precision 3551 which has a
> > > > > > > bluetooth adapter of ID 8087:0026 (Intel AX201). I am using a
> > > > > > > Logitech M575 trackball mouse which only supports Bluetooth LE.
> > > > > > >
> > > > > > > With kernel 6.4.2 or newer, scanning for devices — using either the
> > > > > > > KDE gui or bluetoothctl — most of the time returns only “classic
> > > > > > > bluetooth” devices like computers and phones, and not the mouse. If
> > > > > > > the mouse was paired before, it works correctly however.
> > > > > > >
> > > > > > > With previous kernel versions (6.3.9 and before), pairing the mouse
> > > > > > > worked correctly.
> > > > > >
> > > > > > Are you able to bisect the regression? Please also attach the Linux
> > > > > > messages. (You can also create a ticket in the Linux kernel Bugzilla [1]
> > > > > > and attach everything there.)
> > > > > >
> > > > > >
> > > > > > Kind regards,
> > > > > >
> > > > > > Paul
> > > > > >
> > > > > >
> > > > > > [1]: https://bugzilla.kernel.org/
> > > > > >
> > > > >
> > > > > The offending commit is https://github.com/SUSE/kernel/commit/288c90224eec55d13e786844b7954ef060752089 :
> > > > >
> > > > > > Bluetooth: Enable all supported LE PHY by default
> > > > > > This enables 2M and Coded PHY by default if they are marked as supported
> > > > > > in the LE features bits.
> > > > > >
> > > > > > Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
> > > >
> > > > Do you have the btmon/HCI traces showing this, we also need the
> > > > firmware version as well since I suspect this is due to the controller
> > > > setting the PHYs as supported but being unable to to use them
> > > > properly.
> > > >
> > > >
> > > hciconfig says the below: (I assume “Revision” is the firmware version)
> >
> > You can find the firmware information on dmesg, e.g:
> >
> > [    7.982585] Bluetooth: hci1: Found Intel DDC parameters: intel/ibt-20-1-3.ddc
> > [    7.984113] Bluetooth: hci1: Applying Intel DDC parameters completed
> > [    7.985111] Bluetooth: hci1: Firmware revision 0.3 build 144 week 11 2023
> >
> > > hci0:   Type: Primary  Bus: USB
> > >         BD Address: F0:9E:4A:E6:62:15  ACL MTU: 1021:4  SCO MTU: 96:6
> > >         UP RUNNING
> > >         RX bytes:150050 acl:8114 sco:0 events:270 errors:0
> > >         TX bytes:5970 acl:69 sco:0 commands:173 errors:0
> > >         Features: 0xbf 0xfe 0x0f 0xfe 0xdb 0xff 0x7b 0x87
> > >         Packet type: DM1 DM3 DM5 DH1 DH3 DH5 HV1 HV2 HV3
> > >         Link policy: RSWITCH SNIFF
> > >         Link mode: PERIPHERAL ACCEPT
> > >         Name: '[REDACTED]'
> > >         Class: 0x6c010c
> > >         Service Classes: Rendering, Capturing, Audio, Telephony
> > >         Device Class: Computer, Laptop
> > >         HCI Version: 5.2 (0xb)  Revision: 0x20ce
> > >         LMP Version: 5.2 (0xb)  Subversion: 0x20ce
> > >         Manufacturer: Intel Corp. (2)

The relevant dmesg lines are:

[   10.355916] Bluetooth: hci0: Found device firmware: intel/ibt-19-0-4.sfi
[   10.356067] Bluetooth: hci0: Boot Address: 0x24800
[   10.356070] Bluetooth: hci0: Firmware Version: 206-22.23
[   10.356073] Bluetooth: hci0: Firmware already loaded


> > >
> > > I'm unsure how to attach the btmon output as it is a binary file that contains potentially private information (names of nearby devices)
> >
> > Well you can collect it manually and redacted the addresses, etc, up
> > to you, I'm usually not that paranoid of sharing this kind of
> > information if you scan for a short time, in the other hand I usually
> > use gist.github.com to do that so I can delete it later if needed.
> 
> Seems to be working fine here (with AX201 and AX210):
> 
> https://gist.github.com/Vudentz/d80ab63f4f62f9f216796edb4838c855
> 
> > >
> >
> >
> > --
> > Luiz Augusto von Dentz
> 
> 
> 
> 

Here is a btmon log of me trying to search for devices in a quiet location (the only device seen is the mouse — it shows up in the btmon logs but NOT in the KDE pairing window):
https://gist.github.com/brjsp/f6897ad1431a06820ecdd3773dd4a857