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
