[pulseaudio-discuss] Bluetooth connection disconnects every few minutes

[Georg Chini]

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