Re: Bluetooth connection disconnects every few minutes

[Julian Sikorski <belegdol@gmail.com>]

W dniu 01.09.2020 o 22:10, Julian Sikorski pisze:
> W dniu 12.08.2018 o 17:49, Julian Sikorski pisze:
>> W dniu 01.08.2018 o 19:46, Julian Sikorski pisze:
>>> W dniu 09.07.2018 o 18:51, Julian Sikorski pisze:
>>>> W dniu 08.07.2018 o 19:46, Georg Chini pisze:
>>>>> On 08.07.2018 15:21, Julian Sikorski wrote:
>>>>>> W dniu 02.07.2018 o 20:09, Julian Sikorski pisze:
>>>>>>> W dniu 02.07.2018 o 18:04, Georg Chini pisze:
>>>>>>>> On 02.07.2018 17:58, Julian Sikorski wrote:
>>>>>>>>> W dniu 29.06.2018 o 21:47, Julian Sikorski pisze:
>>>>>>>>>> Hi list,
>>>>>>>>>>
>>>>>>>>>> I have noticed that the bluetooth connection between my laptop (Intel
>>>>>>>>>> 7260) and my headphones (Sennheiser Momentum Wirelless) is very
>>>>>>>>>> unreliable. While under Windows 10 devices stay connected for
>>>>>>>>>> hours on
>>>>>>>>>> end, under Fedora 28 the connection is lost every few minutes at
>>>>>>>>>> most.
>>>>>>>>>> Often the connection will be reestablished only to be lost again.
>>>>>>>>>> bluetoothd shows messages like:
>>>>>>>>>>
>>>>>
>>>>>>>>>> I am not sure where to look further. Does it look like an issue with
>>>>>>>>>> pulseaudio, or a deeper problem with linux bluetooth stack? Thanks
>>>>>>>>>> for
>>>>>>>>>> your input in advance!
>>>>>>>>>>
>>>>>>>>>> Best regards,
>>>>>>>>>> Julian
>>>>>>>>> This is what is logged by pulseaudio at the time the connection is
>>>>>>>>> lost:
>>>>>>>>>
>>>>>>>>> ( 118.064|  34.694) I: [bluetooth] module-bluez5-device.c: FD error:
>>>>>>>>> POLLERR POLLHUP
>>>>>>>>> ( 118.064|   0.000) I: [bluetooth] bluez5-util.c: Transport
>>>>>>>>> /org/bluez/hci0/dev_00_1B_66_81_8D_76/fd27 auto-released by BlueZ or
>>>>>>>>> already released
>>>>>>>>> ( 118.064|   0.000) I: [pulseaudio] backend-native.c: Lost RFCOMM
>>>>>>>>> connection.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>  From what you are writing, it looks to me as if the issue is in the
>>>>>>>> USB
>>>>>>>> stack and the BT dongle keeps disconnecting/connecting. Have you
>>>>>>>> tried another dongle?
>>>>>>> Hi,
>>>>>>>
>>>>>>> I unfortunately do not own any other dongles. I tried getting some
>>>>>>> useful info with btmon but the log seems flooded with way too many
>>>>>>> messages to make anything out.
>>>>>>>
>>>>>> Hi Georg,
>>>>>>
>>>>>> it looks like the problem is more related to how the dongle interacts
>>>>>> with this specific headphone model. I have recently bought another one
>>>>>> for running (AfterShokz Trekz Air) and it works perfectly, connecting
>>>>>> automatically, staying connected and even switching profiles
>>>>>> automatically without issues so far.
>>>>>> The hci0: last event is not cmd complete (0x0f) message seems harmless
>>>>>> as it spams the dmesg output regardless of the device connected (and
>>>>>> also when no device is connected at all.
>>>>>> It appears that whatever is happening it makes the dongle reconnect:
>>>>>>
>>>>>> [nie lip  8 15:14:12 2018] usb 2-1.4: USB disconnect, device number 6
>>>>>> [nie lip  8 15:14:12 2018] usb 2-1.4: new full-speed USB device number 7
>>>>>> using ehci-pci
>>>>>> [nie lip  8 15:14:12 2018] usb 2-1.4: New USB device found,
>>>>>> idVendor=8087, idProduct=07dc, bcdDevice= 0.01
>>>>>> [nie lip  8 15:14:12 2018] usb 2-1.4: New USB device strings: Mfr=0,
>>>>>> Product=0, SerialNumber=0
>>>>>> [nie lip  8 15:14:12 2018] Bluetooth: hci0: read Intel version:
>>>>>> 3707100180012d0d2a
>>>>>> [nie lip  8 15:14:12 2018] Bluetooth: hci0: Intel device is already
>>>>>> patched. patch num: 2a
>>>>>>
>>>>>> Where would you recommend to look for reasons for this behaviour? btmon?
>>>>>> Thank you for the pointers!
>>>>>>
>>>>>> Best regards,
>>>>>> Julian
>>>>>>
>>>>>>
>>>>> Hi Julian,
>>>>>
>>>>> sorry, I have no further ideas. Maybe Luiz can help you to investigate.
>>>>> To me it looks like the headphone is sending something that makes the
>>>>> dongle reset.
>>>>>
>>>>> Regards
>>>>>             Georg
>>>>
>>>> Hi Georg,
>>>>
>>>> no worries - hopefully Luiz will find some time to look into this.
>>>> In the meantime I have been getting acquainted with btmon. I have
>>>> managed to pinpoint the exact moment during which sound stops coming
>>>> through the headphones and starts coming through the laptop speakers. In
>>>> the below testcase, it happens at 18:42:58:
>>>>
>>>> < ACL Data TX: Handle 256 flags 0x02 dlen 850
>>>>                               #1825 [hci0] 18:42:58.908586
>>>>       Channel: 450 len 846 [PSM 25 mode 0] {chan 2}
>>>> < ACL Data TX: Handle 256 flags 0x02 dlen 850
>>>>                               #1826 [hci0] 18:42:58.928877
>>>>       Channel: 450 len 846 [PSM 25 mode 0] {chan 2}
>>>> @ MGMT Event: Class Of Device Changed (0x0007) plen 3
>>>>                            {0x0002} [hci0] 18:43:00.653578
>>>>         Class: 0x000000
>>>>           Major class: Miscellaneous
>>>>           Minor class: 0x00
>>>> @ MGMT Event: Class Of Device Changed (0x0007) plen 3
>>>>                            {0x0001} [hci0] 18:43:00.653578
>>>>         Class: 0x000000
>>>>           Major class: Miscellaneous
>>>>           Minor class: 0x00
>>>> @ MGMT Event: New Settings (0x0006) plen 4
>>>>                            {0x0002} [hci0] 18:43:00.653609
>>>>         Current settings: 0x00000ada
>>>>           Connectable
>>>>           Discoverable
>>>>           Bondable
>>>>           Secure Simple Pairing
>>>>           BR/EDR
>>>>           Low Energy
>>>>           Secure Connections
>>>> @ MGMT Event: New Settings (0x0006) plen 4
>>>>                            {0x0001} [hci0] 18:43:00.653609
>>>>         Current settings: 0x00000ada
>>>>           Connectable
>>>>           Discoverable
>>>>           Bondable
>>>>           Secure Simple Pairing
>>>>           BR/EDR
>>>>           Low Energy
>>>>           Secure Connections
>>>> = bluetoothd: Unable to get io data for Headset Voice gateway:
>>>> getpeername: Transport endpoint is not connected..   18:43:00.654133
>>>> = Close Index: 7C:5C:F8:B2:DF:08
>>>>                                     [hci0] 18:43:00.678348
>>>> @ MGMT Event: Index Removed (0x0005) plen 0
>>>>                            {0x0002} [hci0] 18:43:00.678372
>>>> @ MGMT Event: Index Removed (0x0005) plen 0
>>>>                            {0x0001} [hci0] 18:43:00.678372
>>>> = Delete Index: 7C:5C:F8:B2:DF:08
>>>>                                     [hci0] 18:43:00.678377
>>>> = bluetoothd: Endpoint unregistered: sender=:1.1492
>>>> path=/MediaEndpoint/A2DPSource
>>>> 18:43:00.678966
>>>> = bluetoothd: Endpoint unregistered: sender=:1.1492
>>>> path=/MediaEndpoint/A2DPSink
>>>> 18:43:00.678984
>>>>
>>>> I am copying linux-bluetooth, maybe someone there will have an idea as
>>>> well. Thank you for all your help in advance!
>>>>
>>>> Best regards,
>>>> Julian
>>>
>>> Hi all,
>>>
>>> I tried to get more information using hcidump, but it does not appear
>>> very interesting. I am attaching it here just in case. The last entry
>>> appearing - command complete (read encryption key size) - appears upon
>>> successful connection, not when the connection is dropped. How else
>>> could I try to figure out what is being sent at the time of
>>> disconnection? Thank you!
>>>
>>> Best regards,
>>> Julian
>>
>> Hi list,
>>
>> I just realised I never attached the full btmon dump. Here it goes, the
>> connection drops at 17:32:04:
>>
>> < ACL Data TX: Handle 256 flags 0x02 dlen 850
>>                               #1340 [hci0] 17:32:04.774611
>>       Channel: 450 len 846 [PSM 25 mode 0] {chan 2}
>>> HCI Event: Number of Completed Packets (0x13) plen 5
>>                               #1341 [hci0] 17:32:04.783175
>>         Num handles: 1
>>         Handle: 256
>>         Count: 1
>> < ACL Data TX: Handle 256 flags 0x02 dlen 850
>>                               #1342 [hci0] 17:32:04.794981
>>       Channel: 450 len 846 [PSM 25 mode 0] {chan 2}
>>> HCI Event: Number of Completed Packets (0x13) plen 5
>>                               #1343 [hci0] 17:32:04.803054
>>         Num handles: 1
>>         Handle: 256
>>         Count: 1
>> < ACL Data TX: Handle 256 flags 0x02 dlen 850
>>                               #1344 [hci0] 17:32:04.815326
>>       Channel: 450 len 846 [PSM 25 mode 0] {chan 2}
>>> HCI Event: Number of Completed Packets (0x13) plen 5
>>                               #1345 [hci0] 17:32:04.823198
>>         Num handles: 1
>>         Handle: 256
>>         Count: 1
>> < ACL Data TX: Handle 256 flags 0x02 dlen 850
>>                               #1346 [hci0] 17:32:04.835578
>>       Channel: 450 len 846 [PSM 25 mode 0] {chan 2}
>> < ACL Data TX: Handle 256 flags 0x02 dlen 850
>>                               #1347 [hci0] 17:32:04.856093
>>       Channel: 450 len 846 [PSM 25 mode 0] {chan 2}
>> < ACL Data TX: Handle 256 flags 0x02 dlen 850
>>                               #1348 [hci0] 17:32:04.876186
>>       Channel: 450 len 846 [PSM 25 mode 0] {chan 2}
>> < ACL Data TX: Handle 256 flags 0x02 dlen 850
>>                               #1349 [hci0] 17:32:04.896454
>>       Channel: 450 len 846 [PSM 25 mode 0] {chan 2}
>> < ACL Data TX: Handle 256 flags 0x02 dlen 850
>>                               #1350 [hci0] 17:32:04.916869
>>       Channel: 450 len 846 [PSM 25 mode 0] {chan 2}
>> @ MGMT Event: Class Of Device Changed (0x0007) plen 3
>>                            {0x0002} [hci0] 17:32:06.637019
>>         Class: 0x000000
>>           Major class: Miscellaneous
>>           Minor class: 0x00
>> @ MGMT Event: Class Of Device Changed (0x0007) plen 3
>>                            {0x0001} [hci0] 17:32:06.637019
>>         Class: 0x000000
>>           Major class: Miscellaneous
>>           Minor class: 0x00
>> @ MGMT Event: New Settings (0x0006) plen 4
>>                            {0x0002} [hci0] 17:32:06.637034
>>         Current settings: 0x00000ada
>>           Connectable
>>           Discoverable
>>           Bondable
>>           Secure Simple Pairing
>>           BR/EDR
>>           Low Energy
>>           Secure Connections
>> @ MGMT Event: New Settings (0x0006) plen 4
>>                            {0x0001} [hci0] 17:32:06.637034
>>         Current settings: 0x00000ada
>>           Connectable
>>           Discoverable
>>           Bondable
>>           Secure Simple Pairing
>>           BR/EDR
>>           Low Energy
>>           Secure Connections
>> = Close Index: 7C:5C:F8:B2:DF:08
>>                                     [hci0] 17:32:06.654087
>> @ MGMT Event: Index Removed (0x0005) plen 0
>>                            {0x0002} [hci0] 17:32:06.654114
>> @ MGMT Event: Index Removed (0x0005) plen 0
>>                            {0x0001} [hci0] 17:32:06.654114
>> = Delete Index: 7C:5C:F8:B2:DF:08
>>                                     [hci0] 17:32:06.654120
>> = bluetoothd: Unable to get io data for Headset Voice gateway:
>> getpeername: Transport endpoint is not connected..   17:32:06.654352
>> = bluetoothd: Endpoint unregistered: sender=:1.750
>> path=/MediaEndpoint/A2DPSource
>> 17:32:06.654796
>> = bluetoothd: Endpoint unregistered: sender=:1.750
>> path=/MediaEndpoint/A2DPSink
>> 17:32:06.654836
>>
>> I tried sending the btmon capture as attachment but it appears to be too
>> large for the list, so I uploaded it here instead:
>>
>> https://belegdol.fedorapeople.org/btmon-aug.log
>>
>> Best regards,
>> Julian
>>
> 
> Hi all,
> 
> I have tried the headset again with kernel-5.8.4, bluez-5.54 and
> pulseaudio-13.99.1. The situation has unfortunately not improved in the
> last two years.
> I am attaching the btmon capture of two connection attempts:
> - the first connects and then almost immediately disconnects
> - the second never succeeds
> Does the capture provide any information as to why the connection is
> failing? If I can provide any more data, please let me know. Thanks!
> 
> Best regards,
> Julian
> 
If I am not mistaken, the disconnect happens right after #636

Best regards,
Julian