Bluetooth hangs regularly on Dell XPS 7950

[JamesRichardson]

I use a Matias Bluetooth keyboard. The bluetooth connection hangs regularly multiple times per day. Sometimes "hciconfig hci0 down" then up again will get it working, sometimes not.

Thanks for taking a look.

This is very reproducible. I threw out my old keyboard because i thought it was busted! still happens on new keyboard.

Relevant information:

dmesg:
[68499.490741] Bluetooth: hci0: command 0x2042 tx timeout
[68499.490744] Bluetooth: hci0: No way to reset. Ignoring and continuing
[68499.494750] Bluetooth: hci0: failed to disable LE scan: status 0x1f
...
[68995.230536] Bluetooth: hci0: link tx timeout
[68995.230544] Bluetooth: hci0: killing stalled connection 07:18:10:17:08:56

sniffer:
 HCI Event: LE Meta Event (0x3e) plen 36 #73450 [hci0] 11056.526296
      LE Extended Advertising Report (0x0d)
        Num reports: 1
        Entry 0
          Event type: 0x001a
            Props: 0x001a
              Scannable
              Scan response
              Use legacy advertising PDUs
            Data status: Complete
          Legacy PDU Type: SCAN_RSP to an ADV_IND (0x001a)
          Address type: Random (0x01)
          Address: 5C:C3:EC:5B:FE:FA (Resolvable)
          Primary PHY: LE 1M
          Secondary PHY: No packets
          SID: no ADI field (0xff)
          TX power: 127 dBm
          RSSI: -74 dBm (0xb6)
          Periodic advertising invteral: 0.00 msec (0x0000)
          Direct address type: Public (0x00)
          Direct address: 00:00:00:00:00:00 (OUI 00-00-00)
          Data length: 0x0a
        09 ff e0 00 00 5b ca 5c 12 81 .....[.\..
@ MGMT Event: Device Found (0x0012) plen 52 {0x0002} [hci0] 11056.526421
        LE Address: 5C:C3:EC:5B:FE:FA (Resolvable)
        RSSI: -74 dBm (0xb6)
        Flags: 0x00000004
          Not Connectable
        Data length: 38
        16-bit Service UUIDs (complete): 1 entry
          Google (0xfe9f)
        Service Data (UUID 0xfe9f): 0000000000000000000000000000000000000000
        Company: Google (224)
          Data: 005bca5c1281
@ MGMT Event: Device Found (0x0012) plen 52 {0x0001} [hci0] 11056.526421
        LE Address: 5C:C3:EC:5B:FE:FA (Resolvable)
        RSSI: -74 dBm (0xb6)
        Flags: 0x00000004
          Not Connectable
        Data length: 38
        16-bit Service UUIDs (complete): 1 entry
          Google (0xfe9f)
        Service Data (UUID 0xfe9f): 0000000000000000000000000000000000000000
        Company: Google (224)
          Data: 005bca5c1281
< HCI Command: LE Set Extend.. (0x08|0x0042) plen 6 #73451 [hci0] 11056.730327
        Extended scan: Disabled (0x00)
        Filter duplicates: Disabled (0x00)
        Duration: 0 msec (0x0000)
        Period: 0.00 sec (0x0000)
> HCI Event: Command Complete (0x0e) plen 4 #73452 [hci0] 11056.733306
      LE Set Extended Scan Enable (0x08|0x0042) ncmd 2
        Status: Success (0x00)
< HCI Command: LE Set Extend.. (0x08|0x0042) plen 6 #73453 [hci0] 11056.733366
        Extended scan: Enabled (0x01)
        Filter duplicates: Enabled (0x01)
        Duration: 0 msec (0x0000)
        Period: 0.00 sec (0x0000)
> HCI Event: Command Complete (0x0e) plen 4 #73454 [hci0] 11056.734262
      LE Set Extended Scan Enable (0x08|0x0042) ncmd 2
        Status: Success (0x00)
< ACL Data TX: Handle 256 flags 0x00 dlen 6 #73455 [hci0] 11059.238672
      Channel: 64 len 2 [PSM 0 mode Basic (0x00)] {chan 65535}
        41 03 A.
< HCI Command: Exit Sniff Mode (0x02|0x0004) plen 2 #73456 [hci0] 11059.238708
        Handle: 256
> HCI Event: Command Status (0x0f) plen 4 #73457 [hci0] 11059.395294
      Exit Sniff Mode (0x02|0x0004) ncmd 1
        Status: Success (0x00)
< HCI Command: LE Set Extend.. (0x08|0x0042) plen 6 #73458 [hci0] 11062.514314
        Extended scan: Disabled (0x00)
        Filter duplicates: Disabled (0x00)
        Duration: 0 msec (0x0000)
        Period: 0.00 sec (0x0000)
< ACL Data TX: Handle 256 flags 0x00 dlen 6 #73459 [hci0] 11184.298552
      Channel: 64 len 2 [PSM 0 mode Basic (0x00)] {chan 65535}
        41 03 A.
< ACL Data TX: Handle 256 flags 0x00 dlen 6 #73460 [hci0] 11310.279895
      Channel: 64 len 2 [PSM 0 mode Basic (0x00)] {chan 65535}
        41 03 A.
< ACL Data TX: Handle 256 flags 0x00 dlen 6 #73461 [hci0] 11435.274485
      Channel: 64 len 2 [PSM 0 mode Basic (0x00)] {chan 65535}
        41 03 A.
< HCI Command: Read Clock Of.. (0x01|0x001f) plen 2 #73462 [hci0] 11560.268946
        Handle: 256
> HCI Event: Command Status (0x0f) plen 4 #73463 [hci0] 11560.383549
      Read Clock Offset (0x01|0x001f) ncmd 1
        Status: Success (0x00)
< HCI Command: Disconnect (0x01|0x0006) plen 3 #73464 [hci0] 11560.383612
        Handle: 256
        Reason: Remote User Terminated Connection (0x13)
> HCI Event: Command Status (0x0f) plen 4 #73465 [hci0] 11560.384590
      Disconnect (0x01|0x0006) ncmd 1
        Status: Success (0x00)

hci0: Type: Primary Bus: USB
 BD Address: D0:AB:D5:E5:82:4B ACL MTU: 1021:4 SCO MTU: 96:6
 UP RUNNING PSCAN ISCAN INQUIRY
 RX bytes:3620694 acl:30569 sco:0 events:126583 errors:0
 TX bytes:1316433 acl:490 sco:0 commands:65363 errors:0
 Features: 0xbf 0xfe 0x0f 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: 'james #1'
 Class: 0x1c010c
 Service Classes: Rendering, Capturing, Object Transfer
 Device Class: Computer, Laptop
 HCI Version: 5.1 (0xa) Revision: 0x100
 LMP Version: 5.1 (0xa) Subversion: 0x100
 Manufacturer: Intel Corp. (2)

[JamesRichardson (james-time4tea)]

Just thought i would mention that since I switched off my phone from using the GAEN API, this bug happens a *lot* less. Like almost never. Other people in my house have the GAEN api enabled, so the other phones could potentially be generating whatever signals that caused this issue, but they are much further away & in different rooms.
I don't have any direct evidence that the GAEN API is generating signals that cause this hang, just that it seems to happen a lot less when it is disabled.

[Tony Espy (awe)]

This bug list is meant to track issues with snaps maintained in this project (meant for usage on Ubuntu Core only). If you have issues with bluetooth on Ubuntu Desktop, please use the Ubuntu bluez bug list: https://bugs.launchpad.net/ubuntu/+source/bluez