This bug has persisted over several years, and several versions, and after a lot of investigation I'm not really any closer on what's going on. I have two pretty old GA MA78gm S2H mainboards, configured slightly different, and otherwise working properly. Both of them have run both Ubuntu and Windows. The problem seems to have been minimized when running Win10, and even if it is there it seems like Win10 recover when it happen. I wonder if I started noticing the problem under Ubuntu 14.x, but I'm pretty sure it was there already at Ubuntu 16.x. I'm now running Ubuntu 19.10 and Gnome 3.34.2. It isn't really an option to switch the mainboards, as there are too much custom-builds running on them for the moment. They will probably be replaced when I have time to rebuild everything. ;) To make Bluetooth work I use an ASUS USB-BT400, which report as “BCM920702 Bluetooth 4.0”, or more accurately “BCM20702A1 (001.002.014) build 1467”. I have also used other dongles, but it seems like all of them has the same chipset. Now… Given I restart the computer And boot into Ubuntu 19.10 And log in as myself And attach a pair of Sony MDR-ZX770BN When I listen to sound from a movie with A2DP Then at some random point it start to lag noticeably (sound becomes scratchy) And suddenly disconnects (at this point it seems like it is Bluetooth that disconnects) It may take 5–10 minutes and up to several hours before it disconnects. Given I turn the headphones off And back on When it reconnects to the computer Then the computer fails to enable the sound device (visible in the preference manager f.ex.) There are several reports of various equipments that disconnect, and I wonder if this could be the same problem. Problem 1 The dongle is rather hot when it disconnects. This is mere speculation, but I wonder if the disconnect happen because either the mainboard gives to little current and thus it fails due to voltage drop, or it fails due to overheating. It seems like the port should have enough current to sustain the dongle, but I wonder if the mainboard could let several ports share the same power source, and thus it fail to deliver enough current. There are other devices powered by the USB ports, and they don't seem to fail, which seems likely to happen if power is the issue. The issue seems to be somewhat related to the quality of the audio, which makes me wonder whether higher quality gives more transferred data, which again gives higher power consumption. It also seems like the issue can be triggered by moving away from the computer. That would give higher tx power, which could make the dongle overheat or mainboard could fail to provide enough current. Is there any way to get a more specific failure report from the dongle? Problem 2 After the headphone reconnects it seems like the sound system isn't working properly. I've been checking, and everything seems correct, still the headphone is missing as an output device. I have not been able to figure out what makes the sound system fail, and I have not been able to make it recover. Only way to recover seems to be to do a cold reboot. A simple warm reboot does not fix the problem, but this can be related to problem 1. A few dumps john@hydra:~$ dmesg | fgrep 'Blue' [ 3.089584] usb 1-2.2: Product: BCM920702 Bluetooth 4.0 [ 8.417252] Bluetooth: Core ver 2.22 [ 8.417280] Bluetooth: HCI device and connection manager initialized [ 8.417284] Bluetooth: HCI socket layer initialized [ 8.417286] Bluetooth: L2CAP socket layer initialized [ 8.417301] Bluetooth: SCO socket layer initialized [ 8.779706] Bluetooth: hci0: BCM: chip id 63 [ 8.780703] Bluetooth: hci0: BCM: features 0x07 [ 8.796682] Bluetooth: hci0: hydra [ 8.800667] Bluetooth: hci0: BCM20702A1 (001.002.014) build 1467 [ 9.671568] Bluetooth: hci0: BCM20702A1 (001.002.014) build 1467 [ 9.687584] Bluetooth: hci0: Broadcom Bluetooth Device [ 10.571440] Bluetooth: BNEP (Ethernet Emulation) ver 1.3 [ 10.571442] Bluetooth: BNEP filters: protocol multicast [ 10.571448] Bluetooth: BNEP socket layer initialized [ 630.835385] Bluetooth: RFCOMM TTY layer initialized [ 630.835393] Bluetooth: RFCOMM socket layer initialized [ 630.835398] Bluetooth: RFCOMM ver 1.11 john@hydra:~$ dmesg | fgrep 'sound' [ 7.920552] input: HDA ATI SB Rear Mic as /devices/pci0000:00/0000:00:14.2/sound/card0/input27 [ 7.920612] input: HDA ATI SB Front Mic as /devices/pci0000:00/0000:00:14.2/sound/card0/input28 [ 7.920657] input: HDA ATI SB Line as /devices/pci0000:00/0000:00:14.2/sound/card0/input29 [ 7.920704] input: HDA ATI SB Line Out Front as /devices/pci0000:00/0000:00:14.2/sound/card0/input30 [ 7.920749] input: HDA ATI SB Line Out Surround as /devices/pci0000:00/0000:00:14.2/sound/card0/input31 [ 7.920795] input: HDA ATI SB Line Out CLFE as /devices/pci0000:00/0000:00:14.2/sound/card0/input32 [ 7.920837] input: HDA ATI SB Line Out Side as /devices/pci0000:00/0000:00:14.2/sound/card0/input33 [ 8.686155] input: HDA NVidia HDMI/DP,pcm=3 as /devices/pci0000:00/0000:00:02.0/0000:01:00.1/sound/card1/input34 [ 8.686215] input: HDA NVidia HDMI/DP,pcm=7 as /devices/pci0000:00/0000:00:02.0/0000:01:00.1/sound/card1/input35 [ 8.686264] input: HDA NVidia HDMI/DP,pcm=8 as /devices/pci0000:00/0000:00:02.0/0000:01:00.1/sound/card1/input36 [ 8.686317] input: HDA NVidia HDMI/DP,pcm=9 as /devices/pci0000:00/0000:00:02.0/0000:01:00.1/sound/card1/input37 john@hydra:~$ dmesg | fgrep 'USB' [ 0.418396] ACPI: bus type USB registered [ 1.038660] ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver [ 1.038894] ehci-pci 0000:00:12.2: new USB bus registered, assigned bus number 1 [ 1.038901] ehci-pci 0000:00:12.2: applying AMD SB600/SB700 USB freeze workaround [ 1.053113] ehci-pci 0000:00:12.2: USB 2.0 started, EHCI 1.00 [ 1.053163] usb usb1: New USB device found, idVendor=1d6b, idProduct=0002, bcdDevice= 5.03 [ 1.053165] usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=1 [ 1.053260] hub 1-0:1.0: USB hub found [ 1.053554] ehci-pci 0000:00:13.2: new USB bus registered, assigned bus number 2 [ 1.053565] ehci-pci 0000:00:13.2: applying AMD SB600/SB700 USB freeze workaround [ 1.069110] ehci-pci 0000:00:13.2: USB 2.0 started, EHCI 1.00 [ 1.069167] usb usb2: New USB device found, idVendor=1d6b, idProduct=0002, bcdDevice= 5.03 [ 1.069168] usb usb2: New USB device strings: Mfr=3, Product=2, SerialNumber=1 [ 1.069252] hub 2-0:1.0: USB hub found [ 1.069413] ohci_hcd: USB 1.1 'Open' Host Controller (OHCI) Driver [ 1.069537] ohci-pci 0000:00:12.0: new USB bus registered, assigned bus number 3 [ 1.133139] usb usb3: New USB device found, idVendor=1d6b, idProduct=0001, bcdDevice= 5.03 [ 1.133140] usb usb3: New USB device strings: Mfr=3, Product=2, SerialNumber=1 [ 1.133219] hub 3-0:1.0: USB hub found [ 1.133430] ohci-pci 0000:00:12.1: new USB bus registered, assigned bus number 4 [ 1.197138] usb usb4: New USB device found, idVendor=1d6b, idProduct=0001, bcdDevice= 5.03 [ 1.197139] usb usb4: New USB device strings: Mfr=3, Product=2, SerialNumber=1 [ 1.197215] hub 4-0:1.0: USB hub found [ 1.197418] ohci-pci 0000:00:13.0: new USB bus registered, assigned bus number 5 [ 1.261145] usb usb5: New USB device found, idVendor=1d6b, idProduct=0001, bcdDevice= 5.03 [ 1.261146] usb usb5: New USB device strings: Mfr=3, Product=2, SerialNumber=1 [ 1.261222] hub 5-0:1.0: USB hub found [ 1.261431] ohci-pci 0000:00:13.1: new USB bus registered, assigned bus number 6 [ 1.325138] usb usb6: New USB device found, idVendor=1d6b, idProduct=0001, bcdDevice= 5.03 [ 1.325140] usb usb6: New USB device strings: Mfr=3, Product=2, SerialNumber=1 [ 1.325221] hub 6-0:1.0: USB hub found [ 1.325431] ohci-pci 0000:00:14.5: new USB bus registered, assigned bus number 7 [ 1.344296] usb 1-2: new high-speed USB device number 2 using ehci-pci [ 1.345192] usb usb7: New USB device found, idVendor=1d6b, idProduct=0001, bcdDevice= 5.03 [ 1.345194] usb usb7: New USB device strings: Mfr=3, Product=2, SerialNumber=1 [ 1.345270] hub 7-0:1.0: USB hub found [ 1.345369] uhci_hcd: USB Universal Host Controller Interface driver [ 1.411039] usb 2-3: new high-speed USB device number 2 using ehci-pci [ 1.514751] usb 1-2: New USB device found, idVendor=0bda, idProduct=5411, bcdDevice= 1.17 [ 1.514754] usb 1-2: New USB device strings: Mfr=1, Product=2, SerialNumber=0 [ 1.514755] usb 1-2: Product: 4-Port USB 2.0 Hub [ 1.515556] hub 1-2:1.0: USB hub found [ 1.567748] usb 2-3: New USB device found, idVendor=058f, idProduct=6362, bcdDevice= 1.26 [ 1.567751] usb 2-3: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [ 1.973469] usb 3-3: new full-speed USB device number 2 using ohci-pci [ 2.170518] usb 3-3: New USB device found, idVendor=0d8c, idProduct=0005, bcdDevice= 1.00 [ 2.170520] usb 3-3: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [ 2.170521] usb 3-3: Product: Trust USB microphone [ 2.183643] usbhid: USB HID core driver [ 2.185772] hid-generic 0003:0D8C:0005.0001: hidraw0: USB HID v1.11 Device [MICE MICROPHONE Trust USB microphone] on usb-0000:00:12.0-3/input2 [ 2.505487] usb 1-2.1: new full-speed USB device number 4 using ehci-pci [ 2.617127] usb 1-2.1: New USB device found, idVendor=046d, idProduct=c52b, bcdDevice=12.10 [ 2.617129] usb 1-2.1: New USB device strings: Mfr=1, Product=2, SerialNumber=0 [ 2.617131] usb 1-2.1: Product: USB Receiver [ 2.618805] usb-storage 2-3:1.0: USB Mass Storage device detected [ 2.619057] input: Logitech USB Receiver as /devices/pci0000:00/0000:00:12.2/usb1/1-2/1-2.1/1-2.1:1.0/0003:046D:C52B.0003/input/input6 [ 2.677563] hid-generic 0003:046D:C52B.0003: input,hidraw2: USB HID v1.11 Keyboard [Logitech USB Receiver] on usb-0000:00:12.2-2.1/input0 [ 2.680158] input: Logitech USB Receiver Mouse as /devices/pci0000:00/0000:00:12.2/usb1/1-2/1-2.1/1-2.1:1.1/0003:046D:C52B.0004/input/input7 [ 2.680246] input: Logitech USB Receiver Consumer Control as /devices/pci0000:00/0000:00:12.2/usb1/1-2/1-2.1/1-2.1:1.1/0003:046D:C52B.0004/input/input8 [ 2.737594] input: Logitech USB Receiver System Control as /devices/pci0000:00/0000:00:12.2/usb1/1-2/1-2.1/1-2.1:1.1/0003:046D:C52B.0004/input/input9 [ 2.737717] hid-generic 0003:046D:C52B.0004: input,hiddev1,hidraw3: USB HID v1.11 Mouse [Logitech USB Receiver] on usb-0000:00:12.2-2.1/input1 [ 2.739666] hid-generic 0003:046D:C52B.0005: hiddev2,hidraw4: USB HID v1.11 Device [Logitech USB Receiver] on usb-0000:00:12.2-2.1/input2 [ 2.741464] usb 1-4: new high-speed USB device number 5 using ehci-pci [ 2.931723] usb 1-4: New USB device found, idVendor=045e, idProduct=0772, bcdDevice= 1.13 [ 2.931726] usb 1-4: New USB device strings: Mfr=1, Product=2, SerialNumber=0 [ 2.935880] hid-generic 0003:045E:0772.0006: hiddev3,hidraw5: USB HID v1.01 Device [Microsoft Microsoft® LifeCam Studio(TM)] on usb-0000:00:12.2-4/input4 [ 2.977461] usb 1-2.2: new full-speed USB device number 6 using ehci-pci [ 3.089580] usb 1-2.2: New USB device found, idVendor=0b05, idProduct=17cb, bcdDevice= 1.12 [ 3.089582] usb 1-2.2: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [ 3.169464] usb 1-2.4: new high-speed USB device number 7 using ehci-pci [ 3.278933] usb 1-2.4: New USB device found, idVendor=0bda, idProduct=8153, bcdDevice=30.00 [ 3.278934] usb 1-2.4: New USB device strings: Mfr=1, Product=2, SerialNumber=6 [ 3.278936] usb 1-2.4: Product: USB 10/100/1000 LAN [ 3.446110] logitech-djreceiver 0003:046D:C52B.0005: hiddev1,hidraw2: USB HID v1.11 Device [Logitech USB Receiver] on usb-0000:00:12.2-2.1/input2 [ 3.568023] hid-generic 0003:046D:406B.0007: input,hidraw3: USB HID v1.11 Keyboard [Logitech Unifying Device. Wireless PID:406b] on usb-0000:00:12.2-2.1/input2:1 [ 3.570052] hid-generic 0003:046D:408A.0008: input,hidraw4: USB HID v1.11 Keyboard [Logitech Unifying Device. Wireless PID:408a] on usb-0000:00:12.2-2.1/input2:3 [ 3.642325] scsi 6:0:0:0: Direct-Access Generic USB SD Reader 1.00 PQ: 0 ANSI: 0 [ 3.642811] scsi 6:0:0:1: Direct-Access Generic USB CF Reader 1.01 PQ: 0 ANSI: 0 [ 3.643306] scsi 6:0:0:2: Direct-Access Generic USB SM Reader 1.02 PQ: 0 ANSI: 0 [ 3.643807] scsi 6:0:0:3: Direct-Access Generic USB MS Reader 1.03 PQ: 0 ANSI: 0 [ 3.711373] logitech-hidpp-device 0003:046D:406B.0007: input,hidraw3: USB HID v1.11 Keyboard [Logitech M585/M590] on usb-0000:00:12.2-2.1/input2:1 [ 3.869329] logitech-hidpp-device 0003:046D:408A.0008: input,hidraw4: USB HID v1.11 Keyboard [Logitech MX Keys] on usb-0000:00:12.2-2.1/input2:3 [ 8.349483] usb 1-2.4: reset high-speed USB device number 7 using ehci-pci [ 8.812297] USB Video Class driver (1.1.1) Note that USB 6.1 is edited out of the list. john@hydra:~$ lsb_release -rd Description: Ubuntu 19.10 Release: 19.10 john@hydra:~$ apt-cache policy bluez bluez: Installert: 5.50-0ubuntu5.1 Kandidat: 5.50-0ubuntu5.1 Versjonstabell: *** 5.50-0ubuntu5.1 500 500 http://archive.ubuntu.com/ubuntu eoan-updates/main amd64 Packages 500 http://archive.ubuntu.com/ubuntu eoan-security/main amd64 Packages 100 /var/lib/dpkg/status 5.50-0ubuntu4 500 500 http://archive.ubuntu.com/ubuntu eoan/main amd64 Packages john@hydra:~$ apt-cache policy pulseaudio pulseaudio: Installert: 1:13.0-1ubuntu1.2 Kandidat: 1:13.0-1ubuntu1.2 Versjonstabell: *** 1:13.0-1ubuntu1.2 500 500 http://archive.ubuntu.com/ubuntu eoan-updates/main amd64 Packages 500 http://archive.ubuntu.com/ubuntu eoan-security/main amd64 Packages 100 /var/lib/dpkg/status 1:13.0-1ubuntu1 500 500 http://archive.ubuntu.com/ubuntu eoan/main amd64 Packages john@hydra:~$ apt-cache policy pulseaudio-module-bluetooth pulseaudio-module-bluetooth: Installert: 1:13.0-1ubuntu1.2 Kandidat: 1:13.0-1ubuntu1.2 Versjonstabell: *** 1:13.0-1ubuntu1.2 500 500 http://archive.ubuntu.com/ubuntu eoan-updates/main amd64 Packages 500 http://archive.ubuntu.com/ubuntu eoan-security/main amd64 Packages 100 /var/lib/dpkg/status 1:13.0-1ubuntu1 500 500 http://archive.ubuntu.com/ubuntu eoan/main amd64 Packages After connecting the headphones john@hydra:~$ lsusb Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 002 Device 002: ID 058f:6362 Alcor Micro Corp. Flash Card Reader/Writer Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 001 Device 005: ID 045e:0772 Microsoft Corp. LifeCam Studio Bus 001 Device 007: ID 0bda:8153 Realtek Semiconductor Corp. RTL8153 Gigabit Ethernet Adapter Bus 001 Device 006: ID 0b05:17cb ASUSTek Computer, Inc. Broadcom BCM20702A0 Bluetooth Bus 001 Device 004: ID 046d:c52b Logitech, Inc. Unifying Receiver Bus 001 Device 002: ID 0bda:5411 Realtek Semiconductor Corp. 4-Port USB 2.0 Hub Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 003 Device 002: ID 0d8c:0005 C-Media Electronics, Inc. Blue Snowball Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub john@hydra:~$ hciconfig -a hci0: Type: Primary Bus: USB BD Address: 5C:F3:70:74:FB:30 ACL MTU: 1021:8 SCO MTU: 64:1 UP RUNNING PSCAN RX bytes:66979 acl:42 sco:0 events:9483 errors:0 TX bytes:14324277 acl:16754 sco:0 commands:1003 errors:0 Features: 0xbf 0xfe 0xcf 0xfe 0xdb 0xff 0x7b 0x87 Packet type: DM1 DM3 DM5 DH1 DH3 DH5 HV1 HV2 HV3 Link policy: RSWITCH SNIFF Link mode: SLAVE ACCEPT Name: 'hydra' Class: 0x1c0104 Service Classes: Rendering, Capturing, Object Transfer Device Class: Computer, Desktop workstation HCI Version: 4.0 (0x6) Revision: 0x15bb LMP Version: 4.0 (0x6) Subversion: 0x220e Manufacturer: Broadcom Corporation (15) john@hydra:~$ lsmod Module Size Used by rfcomm 81920 19 nf_conntrack_netlink 45056 0 nfnetlink 16384 2 nf_conntrack_netlink xfrm_user 36864 1 xfrm_algo 16384 1 xfrm_user xt_addrtype 16384 2 br_netfilter 28672 0 xt_CHECKSUM 16384 1 xt_MASQUERADE 20480 4 xt_conntrack 16384 2 ipt_REJECT 16384 2 nf_reject_ipv4 16384 1 ipt_REJECT xt_tcpudp 20480 6 ip6table_mangle 16384 1 ip6table_nat 16384 1 iptable_mangle 16384 1 iptable_nat 16384 1 nf_nat 40960 3 ip6table_nat,iptable_nat,xt_MASQUERADE nf_conntrack 139264 4 xt_conntrack,nf_nat,nf_conntrack_netlink,xt_MASQUERADE nf_defrag_ipv6 24576 1 nf_conntrack nf_defrag_ipv4 16384 1 nf_conntrack ebtable_filter 16384 0 ebtables 36864 1 ebtable_filter ip6table_filter 16384 1 ip6_tables 32768 3 ip6table_filter,ip6table_nat,ip6table_mangle iptable_filter 16384 1 bpfilter 32768 0 bridge 176128 1 br_netfilter stp 16384 1 bridge llc 16384 2 bridge,stp vboxnetadp 28672 0 vboxnetflt 28672 0 vboxdrv 487424 2 vboxnetadp,vboxnetflt aufs 262144 0 overlay 118784 0 cmac 16384 1 bnep 24576 2 uvcvideo 98304 0 btusb 57344 0 btrtl 20480 1 btusb v4l2_common 16384 1 uvcvideo btbcm 16384 1 btusb videobuf2_vmalloc 20480 1 uvcvideo btintel 24576 1 btusb videobuf2_memops 20480 1 videobuf2_vmalloc videobuf2_v4l2 24576 1 uvcvideo bluetooth 581632 51 btrtl,btintel,btbcm,bnep,btusb,rfcomm cdc_ether 20480 0 videobuf2_common 53248 2 videobuf2_v4l2,uvcvideo usbnet 45056 1 cdc_ether joydev 28672 0 input_leds 16384 0 ecdh_generic 16384 2 bluetooth snd_hda_codec_hdmi 61440 1 ecc 28672 1 ecdh_generic r8152 65536 0 videodev 208896 4 v4l2_common,videobuf2_v4l2,uvcvideo,videobuf2_common snd_usb_audio 245760 6 mii 20480 2 usbnet,r8152 snd_usbmidi_lib 36864 1 snd_usb_audio mc 53248 5 videodev,snd_usb_audio,videobuf2_v4l2,uvcvideo,videobuf2_common snd_seq_midi 20480 0 snd_seq_midi_event 16384 1 snd_seq_midi snd_hda_codec_realtek 118784 1 snd_hda_codec_generic 81920 1 snd_hda_codec_realtek ledtrig_audio 16384 2 snd_hda_codec_generic,snd_hda_codec_realtek snd_rawmidi 36864 2 snd_seq_midi,snd_usbmidi_lib edac_mce_amd 32768 0 snd_hda_intel 53248 15 wl 6455296 0 snd_intel_dspcfg 24576 1 snd_hda_intel snd_hda_codec 131072 4 snd_hda_codec_generic,snd_hda_codec_hdmi,snd_hda_intel,snd_hda_codec_realtek snd_hda_core 90112 5 snd_hda_codec_generic,snd_hda_codec_hdmi,snd_hda_intel,snd_hda_codec,snd_hda_codec_realtek snd_seq 69632 2 snd_seq_midi,snd_seq_midi_event snd_hwdep 20480 2 snd_usb_audio,snd_hda_codec serio_raw 20480 0 wmi_bmof 16384 0 k10temp 16384 0 snd_pcm 106496 10 snd_hda_codec_hdmi,snd_hda_intel,snd_usb_audio,snd_hda_codec,snd_hda_core snd_seq_device 16384 3 snd_seq,snd_seq_midi,snd_rawmidi snd_timer 36864 2 snd_seq,snd_pcm snd 90112 50 snd_hda_codec_generic,snd_seq,snd_seq_device,snd_hda_codec_hdmi,snd_hwdep,snd_hda_intel,snd_usb_audio,snd_usbmidi_lib,snd_hda_codec,snd_hda_codec_realtek,snd_timer,snd_pcm,snd_rawmidi cfg80211 712704 1 wl soundcore 16384 1 snd mac_hid 16384 0 nvidia_uvm 970752 0 kvm_amd 98304 0 ccp 94208 1 kvm_amd kvm 659456 1 kvm_amd irqbypass 16384 1 kvm binfmt_misc 24576 1 sch_fq_codel 20480 4 parport_pc 40960 1 ppdev 24576 0 nfsd 380928 13 auth_rpcgss 94208 1 nfsd nfs_acl 16384 1 nfsd lockd 102400 1 nfsd grace 16384 2 nfsd,lockd lp 20480 0 sunrpc 389120 18 nfsd,auth_rpcgss,lockd,nfs_acl parport 53248 3 parport_pc,lp,ppdev ip_tables 32768 3 iptable_filter,iptable_nat,iptable_mangle x_tables 40960 13 ebtables,ip6table_filter,xt_conntrack,iptable_filter,xt_tcpudp,xt_addrtype,xt_CHECKSUM,ip6_tables,ipt_REJECT,ip_tables,ip6table_mangle,xt_MASQUERADE,iptable_mangle autofs4 45056 2 raid10 57344 0 raid456 155648 0 async_raid6_recov 24576 1 raid456 async_memcpy 20480 2 raid456,async_raid6_recov async_pq 24576 2 raid456,async_raid6_recov async_xor 20480 3 async_pq,raid456,async_raid6_recov async_tx 20480 5 async_pq,async_memcpy,async_xor,raid456,async_raid6_recov xor 24576 1 async_xor raid6_pq 114688 3 async_pq,raid456,async_raid6_recov libcrc32c 16384 3 nf_conntrack,nf_nat,raid456 raid0 24576 0 multipath 20480 0 linear 20480 0 hid_logitech_hidpp 40960 0 hid_logitech_dj 24576 0 uas 28672 0 usb_storage 77824 1 uas raid1 45056 1 hid_generic 16384 0 usbhid 57344 1 hid_logitech_dj hid 131072 4 usbhid,hid_generic,hid_logitech_dj,hid_logitech_hidpp nvidia_drm 49152 10 nvidia_modeset 1114112 17 nvidia_drm nvidia 20680704 772 nvidia_uvm,nvidia_modeset drm_kms_helper 184320 1 nvidia_drm syscopyarea 16384 1 drm_kms_helper sysfillrect 16384 1 drm_kms_helper sysimgblt 16384 1 drm_kms_helper fb_sys_fops 16384 1 drm_kms_helper pata_acpi 16384 0 firewire_ohci 40960 0 drm 491520 13 drm_kms_helper,nvidia_drm r8169 81920 0 psmouse 155648 0 ahci 40960 4 pata_atiixp 16384 2 firewire_core 65536 1 firewire_ohci crc_itu_t 16384 1 firewire_core i2c_piix4 28672 0 libahci 32768 1 ahci ipmi_devintf 20480 0 realtek 20480 1 ipmi_msghandler 106496 2 ipmi_devintf,nvidia wmi 32768 1 wmi_bmof john@hydra:~$ sudo hcitool con Connections: > ACL D8:D4:3C:9E:DF:6D handle 11 state 1 lm MASTER AUTH ENCRYPT john@hydra:~$ sudo hcitool name D8:D4:3C:9E:DF:6D MDR-ZX770BN john@hydra:~$ sudo hcitool tpl D8:D4:3C:9E:DF:6D Current transmit power level: 10 john@hydra:~$ sudo hcitool lq D8:D4:3C:9E:DF:6D Link quality: 255 john@hydra:~$ sudo hcitool rssi D8:D4:3C:9E:DF:6D RSSI return value: -24 This time it took nerly four hours before it failed, and the pref managers pane insists that the headphones are connected using A2DP. When the sound stops I get pretty much the same john@hydra:~$ lsusb Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 002 Device 002: ID 058f:6362 Alcor Micro Corp. Flash Card Reader/Writer Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 001 Device 005: ID 045e:0772 Microsoft Corp. LifeCam Studio Bus 001 Device 007: ID 0bda:8153 Realtek Semiconductor Corp. RTL8153 Gigabit Ethernet Adapter Bus 001 Device 006: ID 0b05:17cb ASUSTek Computer, Inc. Broadcom BCM20702A0 Bluetooth Bus 001 Device 004: ID 046d:c52b Logitech, Inc. Unifying Receiver Bus 001 Device 002: ID 0bda:5411 Realtek Semiconductor Corp. 4-Port USB 2.0 Hub Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 003 Device 002: ID 0d8c:0005 C-Media Electronics, Inc. Blue Snowball Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub john@hydra:~$ hciconfig -a hci0: Type: Primary Bus: USB BD Address: 5C:F3:70:74:FB:30 ACL MTU: 1021:8 SCO MTU: 64:1 UP RUNNING PSCAN ISCAN INQUIRY RX bytes:2014977 acl:92 sco:0 events:287627 errors:0 TX bytes:496849978 acl:571824 sco:0 commands:1512 errors:0 Features: 0xbf 0xfe 0xcf 0xfe 0xdb 0xff 0x7b 0x87 Packet type: DM1 DM3 DM5 DH1 DH3 DH5 HV1 HV2 HV3 Link policy: RSWITCH SNIFF Link mode: SLAVE ACCEPT Name: 'hydra' Class: 0x1c0104 Service Classes: Rendering, Capturing, Object Transfer Device Class: Computer, Desktop workstation HCI Version: 4.0 (0x6) Revision: 0x15bb LMP Version: 4.0 (0x6) Subversion: 0x220e Manufacturer: Broadcom Corporation (15) john@hydra:~$ lsmod Module Size Used by rfcomm 81920 19 nf_conntrack_netlink 45056 0 nfnetlink 16384 2 nf_conntrack_netlink xfrm_user 36864 1 xfrm_algo 16384 1 xfrm_user xt_addrtype 16384 2 br_netfilter 28672 0 xt_CHECKSUM 16384 1 xt_MASQUERADE 20480 4 xt_conntrack 16384 2 ipt_REJECT 16384 2 nf_reject_ipv4 16384 1 ipt_REJECT xt_tcpudp 20480 6 ip6table_mangle 16384 1 ip6table_nat 16384 1 iptable_mangle 16384 1 iptable_nat 16384 1 nf_nat 40960 3 ip6table_nat,iptable_nat,xt_MASQUERADE nf_conntrack 139264 4 xt_conntrack,nf_nat,nf_conntrack_netlink,xt_MASQUERADE nf_defrag_ipv6 24576 1 nf_conntrack nf_defrag_ipv4 16384 1 nf_conntrack ebtable_filter 16384 0 ebtables 36864 1 ebtable_filter ip6table_filter 16384 1 ip6_tables 32768 3 ip6table_filter,ip6table_nat,ip6table_mangle iptable_filter 16384 1 bpfilter 32768 0 bridge 176128 1 br_netfilter stp 16384 1 bridge llc 16384 2 bridge,stp vboxnetadp 28672 0 vboxnetflt 28672 0 vboxdrv 487424 2 vboxnetadp,vboxnetflt aufs 262144 0 overlay 118784 0 cmac 16384 1 bnep 24576 2 uvcvideo 98304 0 btusb 57344 0 btrtl 20480 1 btusb v4l2_common 16384 1 uvcvideo btbcm 16384 1 btusb videobuf2_vmalloc 20480 1 uvcvideo btintel 24576 1 btusb videobuf2_memops 20480 1 videobuf2_vmalloc videobuf2_v4l2 24576 1 uvcvideo bluetooth 581632 52 btrtl,btintel,btbcm,bnep,btusb,rfcomm cdc_ether 20480 0 videobuf2_common 53248 2 videobuf2_v4l2,uvcvideo usbnet 45056 1 cdc_ether joydev 28672 0 input_leds 16384 0 ecdh_generic 16384 2 bluetooth snd_hda_codec_hdmi 61440 1 ecc 28672 1 ecdh_generic r8152 65536 0 videodev 208896 4 v4l2_common,videobuf2_v4l2,uvcvideo,videobuf2_common snd_usb_audio 245760 6 mii 20480 2 usbnet,r8152 snd_usbmidi_lib 36864 1 snd_usb_audio mc 53248 5 videodev,snd_usb_audio,videobuf2_v4l2,uvcvideo,videobuf2_common snd_seq_midi 20480 0 snd_seq_midi_event 16384 1 snd_seq_midi snd_hda_codec_realtek 118784 1 snd_hda_codec_generic 81920 1 snd_hda_codec_realtek ledtrig_audio 16384 2 snd_hda_codec_generic,snd_hda_codec_realtek snd_rawmidi 36864 2 snd_seq_midi,snd_usbmidi_lib edac_mce_amd 32768 0 snd_hda_intel 53248 15 wl 6455296 0 snd_intel_dspcfg 24576 1 snd_hda_intel snd_hda_codec 131072 4 snd_hda_codec_generic,snd_hda_codec_hdmi,snd_hda_intel,snd_hda_codec_realtek snd_hda_core 90112 5 snd_hda_codec_generic,snd_hda_codec_hdmi,snd_hda_intel,snd_hda_codec,snd_hda_codec_realtek snd_seq 69632 2 snd_seq_midi,snd_seq_midi_event snd_hwdep 20480 2 snd_usb_audio,snd_hda_codec serio_raw 20480 0 wmi_bmof 16384 0 k10temp 16384 0 snd_pcm 106496 10 snd_hda_codec_hdmi,snd_hda_intel,snd_usb_audio,snd_hda_codec,snd_hda_core snd_seq_device 16384 3 snd_seq,snd_seq_midi,snd_rawmidi snd_timer 36864 2 snd_seq,snd_pcm snd 90112 50 snd_hda_codec_generic,snd_seq,snd_seq_device,snd_hda_codec_hdmi,snd_hwdep,snd_hda_intel,snd_usb_audio,snd_usbmidi_lib,snd_hda_codec,snd_hda_codec_realtek,snd_timer,snd_pcm,snd_rawmidi cfg80211 712704 1 wl soundcore 16384 1 snd mac_hid 16384 0 nvidia_uvm 970752 0 kvm_amd 98304 0 ccp 94208 1 kvm_amd kvm 659456 1 kvm_amd irqbypass 16384 1 kvm binfmt_misc 24576 1 sch_fq_codel 20480 4 parport_pc 40960 1 ppdev 24576 0 nfsd 380928 13 auth_rpcgss 94208 1 nfsd nfs_acl 16384 1 nfsd lockd 102400 1 nfsd grace 16384 2 nfsd,lockd lp 20480 0 sunrpc 389120 18 nfsd,auth_rpcgss,lockd,nfs_acl parport 53248 3 parport_pc,lp,ppdev ip_tables 32768 3 iptable_filter,iptable_nat,iptable_mangle x_tables 40960 13 ebtables,ip6table_filter,xt_conntrack,iptable_filter,xt_tcpudp,xt_addrtype,xt_CHECKSUM,ip6_tables,ipt_REJECT,ip_tables,ip6table_mangle,xt_MASQUERADE,iptable_mangle autofs4 45056 2 raid10 57344 0 raid456 155648 0 async_raid6_recov 24576 1 raid456 async_memcpy 20480 2 raid456,async_raid6_recov async_pq 24576 2 raid456,async_raid6_recov async_xor 20480 3 async_pq,raid456,async_raid6_recov async_tx 20480 5 async_pq,async_memcpy,async_xor,raid456,async_raid6_recov xor 24576 1 async_xor raid6_pq 114688 3 async_pq,raid456,async_raid6_recov libcrc32c 16384 3 nf_conntrack,nf_nat,raid456 raid0 24576 0 multipath 20480 0 linear 20480 0 hid_logitech_hidpp 40960 0 hid_logitech_dj 24576 0 uas 28672 0 usb_storage 77824 1 uas raid1 45056 1 hid_generic 16384 0 usbhid 57344 1 hid_logitech_dj hid 131072 4 usbhid,hid_generic,hid_logitech_dj,hid_logitech_hidpp nvidia_drm 49152 12 nvidia_modeset 1114112 22 nvidia_drm nvidia 20680704 1037 nvidia_uvm,nvidia_modeset drm_kms_helper 184320 1 nvidia_drm syscopyarea 16384 1 drm_kms_helper sysfillrect 16384 1 drm_kms_helper sysimgblt 16384 1 drm_kms_helper fb_sys_fops 16384 1 drm_kms_helper pata_acpi 16384 0 firewire_ohci 40960 0 drm 491520 15 drm_kms_helper,nvidia_drm r8169 81920 0 psmouse 155648 0 ahci 40960 4 pata_atiixp 16384 2 firewire_core 65536 1 firewire_ohci crc_itu_t 16384 1 firewire_core i2c_piix4 28672 0 libahci 32768 1 ahci ipmi_devintf 20480 0 realtek 20480 1 ipmi_msghandler 106496 2 ipmi_devintf,nvidia wmi 32768 1 wmi_bmof john@hydra:~$ sudo hcitool con Connections: > ACL D8:D4:3C:9E:DF:6D handle 12 state 1 lm MASTER AUTH ENCRYPT john@hydra:~$ sudo hcitool name D8:D4:3C:9E:DF:6D MDR-ZX770BN john@hydra:~$ sudo hcitool tpl D8:D4:3C:9E:DF:6D Current transmit power level: 10 At this point, if I try to break the connection from the computer and reconnect, then it will sometimes find the headphone and list it as connected, but it will not be listed in the pref manager as an ouput device. I did that, and made listings like the previous john@hydra:~$ lsusb Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 002 Device 002: ID 058f:6362 Alcor Micro Corp. Flash Card Reader/Writer Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 001 Device 005: ID 045e:0772 Microsoft Corp. LifeCam Studio Bus 001 Device 007: ID 0bda:8153 Realtek Semiconductor Corp. RTL8153 Gigabit Ethernet Adapter Bus 001 Device 006: ID 0b05:17cb ASUSTek Computer, Inc. Broadcom BCM20702A0 Bluetooth Bus 001 Device 004: ID 046d:c52b Logitech, Inc. Unifying Receiver Bus 001 Device 002: ID 0bda:5411 Realtek Semiconductor Corp. 4-Port USB 2.0 Hub Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 003 Device 002: ID 0d8c:0005 C-Media Electronics, Inc. Blue Snowball Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Copy-pasting the lsmod-list made the computer freeze, and I had to make a hard restart, so the error-state is now lost. It could be that something additional was unstable after the error appeared. I provided a dump to give a bit more context on my machine. It is added as an attachment. The actual command to generate the dump is the following, and it was run before the error appeared { sudo lshw | grep product | head -n1 && sudo lspci -knn | grep Net -A3 && lsusb -v; } >output.txt 2>&1 I'll see if I can make the comøputer fail once more, and will then attach the dmesg. It isn't much here to point to the cause of the problem, but perhaps someone familiar with debugging Bluetooth/pulse-audio can point me in the right direction. In particular note hat something is changed for A2DP in Bluez 5.54, and I have not tested this version. (http://www.bluez.org/release-of-bluez-5-54-and-5-53/) If anything else is required I will provide it to the best of my abilities, limited to any security and privacy concerns.