JLink serial (ttyACM0 over usb) drops out, usb device re-enumerates but ttyACM isn't found

[sdpan]

I'm using three nrf52840-dk's, from an ubuntu 16.04 x64 host. 

• JLink v6.30b
• nrfjprog v9.7.2

I can program and interact with two boards fine, with zero of the failures below.  However, the third board is having problems.  This may be the first time I've tried to use the board, and it's always possible there is a HW issue.  I'm hoping to understand what, if any, steps there may be to bring the board back (eg, is there FW on the Jlink or nrf52 side that could possibly be in a bad state that I could fix without scrapping the board).  I've tried different cables; also as mentioned my two other boards work fine.

The problems is that any attempt to write to the ttyACM cause the part to disconnect.

On the board I'm seeing issues:

1. plug in via USB. 
   1. Enumerates fine as both Mass-storage (seems to work fine) and Abstract control module serial (/dev/ttyACM0).
2. Run, for example:  
   1. `nrfjprog -f nrf52 -e --log`
3. The next message on both `dmesg` and `/var/log/syslog` is: 
   1. "Usb disconnect"
4. This is followed by the device re-enumerating ... BUT the ttyACM and filesystem do not come back
5. I can unplug and re-plug the device, and my pc enumerates both the ttyACM and the mass-storage

nrfjprog log:

--------------------------------------------------------------------------------
nrfjprog -f nrf52 -e --log
nrfjprog verion 9.7.2
--------------------------------------------------------------------------------
FUNCTION: open_dll.
FUNCTION: open_dll.
FUNCTION: enum_emu_snr.
FUNCTION: enum_emu_snr.
FUNCTION: enum_emu_snr.
FUNCTION: enum_emu_snr.
FUNCTION: connect_to_emu_with_snr.
FUNCTION: connect_to_emu_with_snr.
FUNCTION: connect_to_emu_without_snr.
FUNCTION: enum_emu_snr.
Updating firmware: J-Link OB-SAM3U128-V2-NordicSemi compiled Jan 12 2018 16:05:20
Replacing firmware: J-Link OB-SAM3U128-V2-NordicSemi compiled Jul 24 2017 17:30:12
JLinkARM.dll OpenEx returned error 'Communication timed out - Can not execute firmware update'.
FUNCTION: close_dll.
FUNCTION: close_dll.
developer@7a2d4d5d225c:~/nRF5_tools/nrf5_sdk/examples/ble_peripheral/ble_app_hts/pca10056/s140/armgcc$ exit
exit

As above, immediately after executing the nrfjprog, the device disconnects, then re-enumerates (but, apparently in a problematic state as ttyACM0 doesn't return)

kernel: [1116808.385970] usb 1-5.1: USB disconnect, device number 64
udisksd[2229]: Cleaning up mount point /media/mike/JLINK1 (device 8:16 no longer exist)
kernel: [1116808.422544] FAT-fs (sdb): unable to read boot sector to mark fs as dirty
kernel: [1116808.654667] usb 1-5.1: new high-speed USB device number 65 using xhci_hcd
mtp-probe: checking bus 1, device 65: "/sys/devices/pci0000:00/0000:00:14.0/usb1/1-5/1-5.1"
mtp-probe: bus: 1, device: 65 was not an MTP device
kernel: [1116808.755452] usb 1-5.1: New USB device found, idVendor=1366, idProduct=0101
kernel: [1116808.755454] usb 1-5.1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
kernel: [1116808.755455] usb 1-5.1: Product: J-Link
kernel: [1116808.755455] usb 1-5.1: Manufacturer: SEGGER
kernel: [1116808.755456] usb 1-5.1: SerialNumber: 000683350409
wpa_supplicant[1618]: wlp2s0: CTRL-EVENT-SCAN-FAILED ret=-100

What can i do to triage / possibly fix this?

[sdpan]

I've tried native-linux, and in a docker container with the necessary devices and permissions mapped. 

FWIW, my normal workflow is from a docker container, as it makes tasks such as rolling new versions, sharing a consistent dev env amoung the team, and standing up automated test boxes trivial compared to local install.  From within a container, i've had no problem with other boards.

I'll look around for a box i can install windows on.  Is there a preferred version?

[sdpan]

huh ... i posted a txt file of this dump here yesterday ... I don't see it now?

[sdpan]

pasting instead of attaching:

Bus 001 Device 085: ID 1366:1015 SEGGER 
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               2.00
  bDeviceClass          239 Miscellaneous Device
  bDeviceSubClass         2 ?
  bDeviceProtocol         1 Interface Association
  bMaxPacketSize0        64
  idVendor           0x1366 SEGGER
  idProduct          0x1015 
  bcdDevice            1.00
  iManufacturer           1 SEGGER
  iProduct                2 J-Link
  iSerial                 3 000683350409
  bNumConfigurations      1
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength          121
    bNumInterfaces          4
    bConfigurationValue     1
    iConfiguration          4 Configuration
    bmAttributes         0x80
      (Bus Powered)
    MaxPower              100mA
    Interface Association:
      bLength                 8
      bDescriptorType        11
      bFirstInterface         0
      bInterfaceCount         2
      bFunctionClass          2 Communications
      bFunctionSubClass       2 Abstract (modem)
      bFunctionProtocol       0 None
      iFunction               5 CDC
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           1
      bInterfaceClass         2 Communications
      bInterfaceSubClass      2 Abstract (modem)
      bInterfaceProtocol      1 AT-commands (v.25ter)
      iInterface              5 CDC
      CDC Header:
        bcdCDC               1.10
      CDC Call Management:
        bmCapabilities       0x03
          call management
          use DataInterface
        bDataInterface          1
      CDC ACM:
        bmCapabilities       0x06
          sends break
          line coding and serial state
      CDC Union:
        bMasterInterface        0
        bSlaveInterface         1 
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x87  EP 7 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0008  1x 8 bytes
        bInterval               8
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        1
      bAlternateSetting       0
      bNumEndpoints           2
      bInterfaceClass        10 CDC Data
      bInterfaceSubClass      0 Unused
      bInterfaceProtocol      0 
      iInterface              6 CDC DATA interface
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x83  EP 3 IN
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0040  1x 64 bytes
        bInterval               1
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x04  EP 4 OUT
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0040  1x 64 bytes
        bInterval               1
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        2
      bAlternateSetting       0
      bNumEndpoints           2
      bInterfaceClass       255 Vendor Specific Class
      bInterfaceSubClass    255 Vendor Specific Subclass
      bInterfaceProtocol    255 Vendor Specific Protocol
      iInterface              7 BULK interface
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x81  EP 1 IN
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0200  1x 512 bytes
        bInterval               1
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x02  EP 2 OUT
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0200  1x 512 bytes
        bInterval               1
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        3
      bAlternateSetting       0
      bNumEndpoints           2
      bInterfaceClass         8 Mass Storage
      bInterfaceSubClass      6 SCSI
      bInterfaceProtocol     80 Bulk-Only
      iInterface              8 MSD interface
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x85  EP 5 IN
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0200  1x 512 bytes
        bInterval               1
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x06  EP 6 OUT
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0200  1x 512 bytes
        bInterval               1
Device Qualifier (for other device speed):
  bLength                10
  bDescriptorType         6
  bcdUSB               2.00
  bDeviceClass          239 Miscellaneous Device
  bDeviceSubClass         2 ?
  bDeviceProtocol         1 Interface Association
  bMaxPacketSize0        64
  bNumConfigurations      1
Device Status:     0x0000
  (Bus Powered)

[sdpan]

I tracked down a windows PC, and installed Segger Embedded Studio latest (3,34) along with SDK 14.2.0

Flashing and running the example works on both board-A (I wasn't having issues on linux with this board)  AND  on board-B.

This made me curious if somehow the windows toolchain had put the board back into a good state ... so I tried both on linux again.

• Board B: still fails, usb disconnect occurs, device re-enumerates but ACM doesn't come back without power cycle
• Board A: programs/run as normal (no change)

unfortunately i just switch to Win; I'll be using pc-ble-driver with a linux host plus other other Linux-specific work.

[sdpan]

Since SES worked on Windows, i tried it on Linux.  I installed it in a docker container per usual

• PITA as your installer does not support a text mode.  Can this please be submitted as a feature request?  All installers should support text mode.
• Note also, since it's a gui program, X must be mapped in.  Obviously this doesn't leverage anything 'sandboxing' as in some container use cases - the reason we attempt to put tools in a container is, as mentioned earlier, repeatability, makes bringing new engineers/computers/test-nodes trivial

Anyway, Both Board-A and Board-B flash and run find under SES Linux, in a container.

What's the difference between these two flows?  nrf-commandline-tools using JLink differently than SES?  Definitely seems like a problem outside my machine .. although I'm not so sure about how i can make a "bug-jar" for you.