Bang & Olufsen Cisco 980 loses connection on 6.5 generic kernel

[David Ober]

When you connect the headset which is based on Bluetooth LE it connects and then almost immediately disconnects. This does not happen when using the 6.5.0-1009-oem kernel Can you poirt whatever changes to bluetooth from the oem kernel to the generic as the cutomer will not use the oem kernels

[AaronMa (mapengyu)]

@David

could you upload the whole dmesg and lsusb?

For a quick check, the only diff is MT7925.

Is this your bluetooth chip?

[David Ober (dober60)]

Dmesg log from OEM kernel

[David Ober (dober60)]

lsusb output

[AaronMa (mapengyu)]

@David,

It's an Intel AX201 chip:

[ 3.079924] Bluetooth: hci0: Found device firmware: intel/ibt-19-0-4.sfi
[ 3.079937] Bluetooth: hci0: Boot Address: 0x24800
[ 3.079939] Bluetooth: hci0: Firmware Version: 126-5.22

There is no difference between 6.5 jammy kernel and 6.5-oem kernel.

[David Ober (dober60)]

All though you state that there is no difference in the two the LE functionality of the headset works on the OEM kernel and does not work n the Jammy generic kernel.

David

-----Original Message-----
From: <email address hidden> <email address hidden> On Behalf Of AaronMa
Sent: Thursday, February 22, 2024 7:18 AM
To: David Ober <email address hidden>
Subject: [External] [Bug 2049938] Re: Bang & Olufsen Cisco 980 loses connection on 6.5 generic kernel

@David,

It's an Intel AX201 chip:

[ 3.079924] Bluetooth: hci0: Found device firmware: intel/ibt-19-0-4.sfi
[ 3.079937] Bluetooth: hci0: Boot Address: 0x24800
[ 3.079939] Bluetooth: hci0: Firmware Version: 126-5.22

There is no difference between 6.5 jammy kernel and 6.5-oem kernel.

--
You received this bug notification because you are a member of The Sutton Team, which is a bug assignee.
https://bugs.launchpad.net/bugs/2049938

Title:
  Bang & Olufsen Cisco 980 loses connection on 6.5 generic kernel

Status in linux package in Ubuntu:
  New

Bug description:
  When you connect the headset which is based on Bluetooth LE it
  connects and then almost immediately disconnects. This does not
  happen when using the 6.5.0-1009-oem kernel Can you poirt whatever
  changes to bluetooth from the oem kernel to the generic as the cutomer
  will not use the oem kernels

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2049938/+subscriptions

[Peter Zhang - Lenovo (zhangfp1)]

@Aaron，As just talked, can you help to double check it? Besides the kernel, are there any other aspects that can impact the result? Our account rep wonder if you need a meeting with the customer or you need the HW to debug the issue? From the dmesg, it is ThinkPad X1 Carbon Gen 9. Thanks.

[AaronMa (mapengyu)]

Ubuntu Jammy 6.5 kernel is located in:
https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/jammy hwe-6.5-next

Ubuntu Jammy oem kernel is located in:
https://git.launchpad.net/~canonical-kernel/ubuntu/+source/linux-oem/+git/jammy oem-6.5-next

the only diff from Ubuntu 6.5.0-17 to the kernel oem-6.5.0-1009 is following:
git diff Ubuntu-6.5.0-17.17..Ubuntu-oem-6.5-6.5.0-1009.10 drivers/bluetooth/
diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index cc1a1315e478..b99befd9d1f5 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -631,24 +631,9 @@ static const struct usb_device_id blacklist_table[] = {
        { USB_DEVICE(0x0489, 0xe0e4), .driver_info = BTUSB_MEDIATEK |
                                                     BTUSB_WIDEBAND_SPEECH |
                                                     BTUSB_VALID_LE_STATES },
- { USB_DEVICE(0x0489, 0xe0f1), .driver_info = BTUSB_MEDIATEK |
- BTUSB_WIDEBAND_SPEECH |
- BTUSB_VALID_LE_STATES },
        { USB_DEVICE(0x0489, 0xe0f2), .driver_info = BTUSB_MEDIATEK |
                                                     BTUSB_WIDEBAND_SPEECH |
                                                     BTUSB_VALID_LE_STATES },
- { USB_DEVICE(0x0489, 0xe0f5), .driver_info = BTUSB_MEDIATEK |
- BTUSB_WIDEBAND_SPEECH |
- BTUSB_VALID_LE_STATES },
- { USB_DEVICE(0x0489, 0xe0f6), .driver_info = BTUSB_MEDIATEK |
- BTUSB_WIDEBAND_SPEECH |
- BTUSB_VALID_LE_STATES },
- { USB_DEVICE(0x0489, 0xe102), .driver_info = BTUSB_MEDIATEK |
- BTUSB_WIDEBAND_SPEECH |
- BTUSB_VALID_LE_STATES },
- { USB_DEVICE(0x04ca, 0x3804), .driver_info = BTUSB_MEDIATEK |
- BTUSB_WIDEBAND_SPEECH |
- BTUSB_VALID_LE_STATES },

        /* Additional Realtek 8723AE Bluetooth devices */
        { USB_DEVICE(0x0930, 0x021d), .driver_info = BTUSB_REALTEK },

[AaronMa (mapengyu)]

@David,

Could you provide the dmesg of 6.5 generic kernel after reproduced the issue?

[AaronMa (mapengyu)]

Gabriel help me find one X1C9. I will try to reproduce the issue after I got it.

[AaronMa (mapengyu)]

Tested BT on X1C9 with 22.04.4 with 6.5.0-18-generic kernel.

Bus 003 Device 005: ID 8087:0026 Intel Corp. AX201 Bluetooth
Device Descriptor:
  bLength 18
  bDescriptorType 1
  bcdUSB 2.01
  bDeviceClass 224 Wireless
  bDeviceSubClass 1 Radio Frequency
  bDeviceProtocol 1 Bluetooth
  bMaxPacketSize0 64
  idVendor 0x8087 Intel Corp.
  idProduct 0x0026 AX201 Bluetooth

Both SENNHEISER HD250BT and AirPods works fine after paired.
AirPods tried 3 times to pair. But works fine after that.

dmesg attached.

[AaronMa (mapengyu)]

From dmesg, I found your BT firmware is old one.
[ 5.038223] Bluetooth: hci0: Firmware revision 0.4 build 126 week 5 2022

22.04.4 log:
[ 528.128307] Bluetooth: hci0: Firmware revision 0.4 build 206 week 22 2023

After downgrade linux-firmware to:20220329.git681281e4-0ubuntu3.14

With the same BT fw, BT headphones works fine too.

BT LE feature on this AX201 revision should be disabled in driver by default:
[ 5.040245] Bluetooth: hci0: HCI LE Coded PHY feature bit is set, but its usage is not supported.

[David Ober (dober60)]

tested using 24.04 on X1 Carbon 12 AX211 seems to work using the generic kernel, testing on the AX201 on the Carbon 9 did not work

[AaronMa (mapengyu)]

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2068754/comments/2