USB serial throughput issues / dropped bytes / failed reads

Product support balenaOS
,
1

Hello.

We have a project that has a couple of containers that both need access to two specific (and present at boot) USB serial devices (by SiLabs and NXP). The devices are listed in /dev/tty*.

While the devices are available to the containers (via privileged mode or devices config in docker.compose.yml), we are experiencing issues with throughput / dropped bytes between PySerial and the devices. In fact we have seen situations where on opening one device, the other throws data errors, indicating there is some process in the middle that is causing the issue. (Once device is /dev/ttyUSB0 and the other is /dev/ttyACM0)

The system is currently running balenaOS 2.31.5+rev1 and supervisor 9.11.3, although this problem persists into the newer base systems.

Here is a snippet of the configuration:

  serial:
    restart: always
    build: ./serial
    privileged: true
    network_mode: host
    expose:
      - "8080"
    volumes:
      - 'shared:/var/shared'
    devices:
      - "/dev/rtc:/dev/rtc"
      - "/dev/ttyUSB0:/dev/ttyUSB0"
    cap_add:
      - SYS_TIME
    labels:
      io.balena.features.kernel-modules: '1'
      io.balena.features.dbus: '1'
      io.balena.features.supervisor-api: '1'

When the data is corrupt / not available, pyserial throws the following errror:
... device reports readiness to read but returned no data ...

This leads me to want to understand better how to eek out the maxium performance between a docker container and the base OS so that the fewer man-in-the-middle processes cause delays / corruption / bottlenecks.

We have tried to disable UART in the device config (on the Balena platform), but this has had no effect. We have also tried to mask off the serial-getty service, as indicated in this post.

Any tips or guidance would be appreciated and I will report back here if I find anything of note.

Thanks.

2

Just to clarify, the container(s) start OK and generally connect to the device(s) OK (might take a few attempts). That’s not so much of the issue (although likely related) - where there is a problem is when there are byte read failures later on in the program.

Our code can cope with read issues and malformed packets, but if the same code is run on a native Raspbian image or other Python-based OSes, there are never read / write issues. We only see the issues when run within a Balena / Docker container.

I should have added this to the original post!

3

Hi,

Can you please grant support access and send us the device UUID so we can have a look?
It’s hard to investigate these kinds of error but I think we can look at the dmesg output for kernel logs when the issue occurs to see if it reports any underlying issue.

4

Hi there. I will connect it all up and send the info over. It has not had the read issues since I sent the email (!), so this might be hard to diagnose! :slight_smile:

5

Since you mentioned the serial-getty service, are you using the development image as I think only dev image has this service. If so please change to production image and try again as we use some serials on the dev image so you might not be able to use them.

6

No - I am using a production image. The serial-getty thing was something I tried - I had no expectation of it to work or what it was actually doing! :slight_smile:

7

Thank you, please try to collect the dmesg output when the issue occurs and let us know and we will have a look into it.

8

@nghiant2710 - I have sent you a message with details. Thanks.

UUID shared with support.

10

I have restarted the system and the container had trouble starting the USB device the first few attempts. Nothing of note in dmesg.

First device we want to get working at /dev/ttyUSB0 is idVendor=10c4, idProduct=8a5b.

[    0.000000] Booting Linux on physical CPU 0x0
[    0.000000] Linux version 4.14.98 (oe-user@oe-host) (gcc version 7.3.0 (GCC)) #1 SMP Fri Mar 22 06:23:54 UTC 2019
[    0.000000] CPU: ARMv7 Processor [410fd034] revision 4 (ARMv7), cr=10c5383d
[    0.000000] CPU: div instructions available: patching division code
[    0.000000] CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache
[    0.000000] OF: fdt: Machine model: Raspberry Pi 3 Model B Plus Rev 1.3
[    0.000000] Memory policy: Data cache writealloc
[    0.000000] cma: Reserved 8 MiB at 0x3dc00000
[    0.000000] On node 0 totalpages: 255488
[    0.000000] free_area_init_node: node 0, pgdat 8148aec0, node_mem_map bd336000
[    0.000000]   Normal zone: 2246 pages used for memmap
[    0.000000]   Normal zone: 0 pages reserved
[    0.000000]   Normal zone: 255488 pages, LIFO batch:31
[    0.000000] random: get_random_bytes called from start_kernel+0xac/0x448 with crng_init=0
[    0.000000] percpu: Embedded 17 pages/cpu @be59c000 s38796 r8192 d22644 u69632
[    0.000000] pcpu-alloc: s38796 r8192 d22644 u69632 alloc=17*4096
[    0.000000] pcpu-alloc: [0] 0 [0] 1 [0] 2 [0] 3 
[    0.000000] Built 1 zonelists, mobility grouping on.  Total pages: 253242
[    0.000000] Kernel command line: 8250.nr_uarts=0 bcm2708_fb.fbwidth=656 bcm2708_fb.fbheight=416 bcm2708_fb.fbdepth=16 bcm2708_fb.fbswap=1 vc_mem.mem_base=0x3f000000 vc_mem.mem_size=0x3f600000  dwc_otg.lpm_enable=0 console=null rootfstype=ext4 rootwait vt.global_cursor_default=0 root=PARTUUID=cf17c89d-02 rootwait
[    0.000000] PID hash table entries: 4096 (order: 2, 16384 bytes)
[    0.000000] Dentry cache hash table entries: 131072 (order: 7, 524288 bytes)
[    0.000000] Inode-cache hash table entries: 65536 (order: 6, 262144 bytes)
[    0.000000] Memory: 982732K/1021952K available (8192K kernel code, 600K rwdata, 2256K rodata, 8192K init, 705K bss, 31028K reserved, 8192K cma-reserved)
[    0.000000] Virtual kernel memory layout:
                   vector  : 0xffff0000 - 0xffff1000   (   4 kB)
                   fixmap  : 0xffc00000 - 0xfff00000   (3072 kB)
                   vmalloc : 0xbe800000 - 0xff800000   (1040 MB)
                   lowmem  : 0x80000000 - 0xbe600000   ( 998 MB)
                   modules : 0x7f000000 - 0x80000000   (  16 MB)
                     .text : 0x80008000 - 0x80900000   (9184 kB)
                     .init : 0x80c00000 - 0x81400000   (8192 kB)
                     .data : 0x81400000 - 0x8149621c   ( 601 kB)
                      .bss : 0x8149e6e4 - 0x8154ee30   ( 706 kB)
[    0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=4, Nodes=1
[    0.000000] ftrace: allocating 27624 entries in 82 pages
[    0.000000] Hierarchical RCU implementation.
[    0.000000] NR_IRQS: 16, nr_irqs: 16, preallocated irqs: 16
[    0.000000] arch_timer: cp15 timer(s) running at 19.20MHz (phys).
[    0.000000] clocksource: arch_sys_counter: mask: 0xffffffffffffff max_cycles: 0x46d987e47, max_idle_ns: 440795202767 ns
[    0.000007] sched_clock: 56 bits at 19MHz, resolution 52ns, wraps every 4398046511078ns
[    0.000022] Switching to timer-based delay loop, resolution 52ns
[    0.000277] Console: colour dummy device 80x30
[    0.000311] Calibrating delay loop (skipped), value calculated using timer frequency.. 38.40 BogoMIPS (lpj=192000)
[    0.000330] pid_max: default: 32768 minimum: 301
[    0.000646] Mount-cache hash table entries: 2048 (order: 1, 8192 bytes)
[    0.000666] Mountpoint-cache hash table entries: 2048 (order: 1, 8192 bytes)
[    0.001522] CPU: Testing write buffer coherency: ok
[    0.001952] CPU0: thread -1, cpu 0, socket 0, mpidr 80000000
[    0.002374] Setting up static identity map for 0x100000 - 0x10003c
[    0.002502] Hierarchical SRCU implementation.
[    0.003188] smp: Bringing up secondary CPUs ...
[    0.003960] CPU1: thread -1, cpu 1, socket 0, mpidr 80000001
[    0.004774] CPU2: thread -1, cpu 2, socket 0, mpidr 80000002
[    0.005567] CPU3: thread -1, cpu 3, socket 0, mpidr 80000003
[    0.005673] smp: Brought up 1 node, 4 CPUs
[    0.005701] SMP: Total of 4 processors activated (153.60 BogoMIPS).
[    0.005710] CPU: All CPU(s) started in HYP mode.
[    0.005718] CPU: Virtualization extensions available.
[    0.006661] devtmpfs: initialized
[    0.017320] VFP support v0.3: implementor 41 architecture 3 part 40 variant 3 rev 4
[    0.017538] clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604462750000 ns
[    0.017560] futex hash table entries: 1024 (order: 4, 65536 bytes)
[    0.018140] pinctrl core: initialized pinctrl subsystem
[    0.018885] NET: Registered protocol family 16
[    0.021468] DMA: preallocated 1024 KiB pool for atomic coherent allocations
[    0.026153] hw-breakpoint: found 5 (+1 reserved) breakpoint and 4 watchpoint registers.
[    0.026166] hw-breakpoint: maximum watchpoint size is 8 bytes.
[    0.026379] Serial: AMBA PL011 UART driver
[    0.028125] bcm2835-mbox 3f00b880.mailbox: mailbox enabled
[    0.028582] uart-pl011 3f201000.serial: could not find pctldev for node /soc/gpio@7e200000/uart0_pins, deferring probe
[    0.059762] bcm2835-dma 3f007000.dma: DMA legacy API manager at be813000, dmachans=0x1
[    0.061312] SCSI subsystem initialized
[    0.061539] usbcore: registered new interface driver usbfs
[    0.061595] usbcore: registered new interface driver hub
[    0.061685] usbcore: registered new device driver usb
[    0.070076] raspberrypi-firmware soc:firmware: Attached to firmware from 2018-11-04 16:32
[    0.071352] clocksource: Switched to clocksource arch_sys_counter
[    0.153617] VFS: Disk quotas dquot_6.6.0
[    0.153709] VFS: Dquot-cache hash table entries: 1024 (order 0, 4096 bytes)
[    0.153898] FS-Cache: Loaded
[    0.154107] CacheFiles: Loaded
[    0.162966] NET: Registered protocol family 2
[    0.163687] TCP established hash table entries: 8192 (order: 3, 32768 bytes)
[    0.163801] TCP bind hash table entries: 8192 (order: 4, 65536 bytes)
[    0.163991] TCP: Hash tables configured (established 8192 bind 8192)
[    0.164124] UDP hash table entries: 512 (order: 2, 16384 bytes)
[    0.164172] UDP-Lite hash table entries: 512 (order: 2, 16384 bytes)
[    0.164398] NET: Registered protocol family 1
[    0.164934] RPC: Registered named UNIX socket transport module.
[    0.164946] RPC: Registered udp transport module.
[    0.164955] RPC: Registered tcp transport module.
[    0.164964] RPC: Registered tcp NFSv4.1 backchannel transport module.
[    0.224240] hw perfevents: enabled with armv7_cortex_a7 PMU driver, 7 counters available
[    0.226977] workingset: timestamp_bits=14 max_order=18 bucket_order=4
[    0.234654] squashfs: version 4.0 (2009/01/31) Phillip Lougher
[    0.234924] FS-Cache: Netfs 'nfs' registered for caching
[    0.235541] NFS: Registering the id_resolver key type
[    0.235587] Key type id_resolver registered
[    0.235597] Key type id_legacy registered
[    0.235617] nfs4filelayout_init: NFSv4 File Layout Driver Registering...
[    0.236830] aufs 4.14.73+-20190211
[    0.238044] Block layer SCSI generic (bsg) driver version 0.4 loaded (major 251)
[    0.238170] io scheduler noop registered
[    0.238182] io scheduler deadline registered
[    0.238346] io scheduler cfq registered (default)
[    0.238358] io scheduler mq-deadline registered
[    0.238368] io scheduler kyber registered
[    0.240728] BCM2708FB: allocated DMA memory fdd00000
[    0.240761] BCM2708FB: allocated DMA channel 0 @ be813000
[    0.245769] Console: switching to colour frame buffer device 82x26
[    0.250139] bcm2835-rng 3f104000.rng: hwrng registered
[    0.250277] vc-mem: phys_addr:0x00000000 mem_base=0x3f000000 mem_size:0x3f600000(1014 MiB)
[    0.250736] vc-sm: Videocore shared memory driver
[    0.251018] gpiomem-bcm2835 3f200000.gpiomem: Initialised: Registers at 0x3f200000
[    0.260417] brd: module loaded
[    0.269243] loop: module loaded
[    0.269264] Loading iSCSI transport class v2.0-870.
[    0.269943] libphy: Fixed MDIO Bus: probed
[    0.269985] tun: Universal TUN/TAP device driver, 1.6
[    0.270146] dwc_otg: version 3.00a 10-AUG-2012 (platform bus)
[    0.270405] dwc_otg 3f980000.usb: base=0xf0980000
[    0.470587] Core Release: 2.80a
[    0.470600] Setting default values for core params
[    0.470628] Finished setting default values for core params
[    0.670867] Using Buffer DMA mode
[    0.670878] Periodic Transfer Interrupt Enhancement - disabled
[    0.670888] Multiprocessor Interrupt Enhancement - disabled
[    0.670898] OTG VER PARAM: 0, OTG VER FLAG: 0
[    0.670925] Dedicated Tx FIFOs mode
[    0.671298] WARN::dwc_otg_hcd_init:1046: FIQ DMA bounce buffers: virt = 0xbdd14000 dma = 0xfdd14000 len=9024
[    0.671327] FIQ FSM acceleration enabled for :
               Non-periodic Split Transactions
               Periodic Split Transactions
               High-Speed Isochronous Endpoints
               Interrupt/Control Split Transaction hack enabled
[    0.671375] dwc_otg: Microframe scheduler enabled
[    0.671430] WARN::hcd_init_fiq:459: FIQ on core 1 at 0x80647c48
[    0.671446] WARN::hcd_init_fiq:460: FIQ ASM at 0x80647fa4 length 36
[    0.671463] WARN::hcd_init_fiq:486: MPHI regs_base at 0xf0006000
[    0.671520] dwc_otg 3f980000.usb: DWC OTG Controller
[    0.671556] dwc_otg 3f980000.usb: new USB bus registered, assigned bus number 1
[    0.671591] dwc_otg 3f980000.usb: irq 62, io mem 0x00000000
[    0.671642] Init: Port Power? op_state=1
[    0.671651] Init: Power Port (0)
[    0.671855] usb usb1: New USB device found, idVendor=1d6b, idProduct=0002
[    0.671870] usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=1
[    0.671883] usb usb1: Product: DWC OTG Controller
[    0.671896] usb usb1: Manufacturer: Linux 4.14.98 dwc_otg_hcd
[    0.671908] usb usb1: SerialNumber: 3f980000.usb
[    0.672502] hub 1-0:1.0: USB hub found
[    0.672545] hub 1-0:1.0: 1 port detected
[    0.673018] dwc_otg: FIQ enabled
[    0.673024] dwc_otg: NAK holdoff enabled
[    0.673028] dwc_otg: FIQ split-transaction FSM enabled
[    0.673037] Module dwc_common_port init
[    0.673251] usbcore: registered new interface driver usb-storage
[    0.673418] mousedev: PS/2 mouse device common for all mice
[    0.673493] IR NEC protocol handler initialized
[    0.673503] IR RC5(x/sz) protocol handler initialized
[    0.673512] IR RC6 protocol handler initialized
[    0.673521] IR JVC protocol handler initialized
[    0.673529] IR Sony protocol handler initialized
[    0.673538] IR SANYO protocol handler initialized
[    0.673547] IR Sharp protocol handler initialized
[    0.673556] IR MCE Keyboard/mouse protocol handler initialized
[    0.673565] IR XMP protocol handler initialized
[    0.674249] bcm2835-wdt 3f100000.watchdog: Broadcom BCM2835 watchdog timer
[    0.674521] bcm2835-cpufreq: min=600000 max=1400000
[    0.674913] sdhci: Secure Digital Host Controller Interface driver
[    0.674923] sdhci: Copyright(c) Pierre Ossman
[    0.675284] mmc-bcm2835 3f300000.mmc: could not get clk, deferring probe
[    0.675610] sdhost-bcm2835 3f202000.mmc: could not get clk, deferring probe
[    0.675711] sdhci-pltfm: SDHCI platform and OF driver helper
[    0.679087] ledtrig-cpu: registered to indicate activity on CPUs
[    0.679158] hidraw: raw HID events driver (C) Jiri Kosina
[    0.679219] usbcore: registered new interface driver usbhid
[    0.679223] usbhid: USB HID core driver
[    0.679531] vchiq: vchiq_init_state: slot_zero = bdd80000, is_master = 0
[    0.680410] [vc_sm_connected_init]: start
[    0.683156] vc_vchi_sm_init: failed to open VCHI service (-1)
[    0.683160] [vc_sm_connected_init]: failed to initialize shared memory service
[    0.683168] [vc_sm_connected_init]: end - returning -1
[    0.683537] nf_conntrack version 0.5.0 (16384 buckets, 65536 max)
[    0.683884] ip_tables: (C) 2000-2006 Netfilter Core Team
[    0.684166] Initializing XFRM netlink socket
[    0.684458] NET: Registered protocol family 10
[    0.684912] Segment Routing with IPv6
[    0.684948] NET: Registered protocol family 17
[    0.684974] bridge: filtering via arp/ip/ip6tables is no longer available by default. Update your scripts to load br_netfilter if you need this.
[    0.685016] Key type dns_resolver registered
[    0.685190] Registering SWP/SWPB emulation handler
[    0.685482] registered taskstats version 1
[    0.688347] uart-pl011 3f201000.serial: cts_event_workaround enabled
[    0.688393] 3f201000.serial: ttyAMA0 at MMIO 0x3f201000 (irq = 87, base_baud = 0) is a PL011 rev2
[    0.689331] mmc-bcm2835 3f300000.mmc: mmc_debug:0 mmc_debug2:0
[    0.689338] mmc-bcm2835 3f300000.mmc: DMA channel allocated
[    0.741979] sdhost: log_buf @ bdd13000 (fdd13000)
[    0.779214] mmc1: queuing unknown CIS tuple 0x80 (2 bytes)
[    0.780707] mmc1: queuing unknown CIS tuple 0x80 (3 bytes)
[    0.782200] mmc1: queuing unknown CIS tuple 0x80 (3 bytes)
[    0.784960] mmc1: queuing unknown CIS tuple 0x80 (7 bytes)
[    0.821373] mmc0: sdhost-bcm2835 loaded - DMA enabled (>1)
[    0.822333] of_cfs_init
[    0.822415] of_cfs_init: OK
[    0.822718] Warning: unable to open an initial console.
[    0.835041] Freeing unused kernel memory: 8192K
[    0.873049] random: fast init done
[    0.880289] mmc1: new high speed SDIO card at address 0001
[    0.891558] Indeed it is in host mode hprt0 = 00021501
[    0.992532] mmc0: host does not support reading read-only switch, assuming write-enable
[    0.996586] mmc0: new high speed SDHC card at address aaaa
[    0.996975] mmcblk0: mmc0:aaaa SL16G 14.8 GiB
[    1.000742]  mmcblk0: p1 p2 p3 p4 < p5 p6 >
[    1.101434] usb 1-1: new high-speed USB device number 2 using dwc_otg
[    1.101595] Indeed it is in host mode hprt0 = 00001101
[    1.128880] udevd[256]: starting version 237
[    1.341779] usb 1-1: New USB device found, idVendor=0424, idProduct=2514
[    1.341804] usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
[    1.342510] hub 1-1:1.0: USB hub found
[    1.342615] hub 1-1:1.0: 4 ports detected
[    1.661384] usb 1-1.1: new high-speed USB device number 3 using dwc_otg
[    1.791551] usb 1-1.1: New USB device found, idVendor=0424, idProduct=2514
[    1.791564] usb 1-1.1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
[    1.791948] hub 1-1.1:1.0: USB hub found
[    1.791994] hub 1-1.1:1.0: 3 ports detected
[    1.891454] usb 1-1.3: new full-speed USB device number 4 using dwc_otg
[    2.028600] usb 1-1.3: New USB device found, idVendor=10c4, idProduct=8a5b
[    2.028626] usb 1-1.3: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[    2.028640] usb 1-1.3: Product: CEL EM3588 Zigbee USB Stick
[    2.028653] usb 1-1.3: Manufacturer: Silicon Labs
[    2.028665] usb 1-1.3: SerialNumber: 013C82CA
[    2.219744] EXT4-fs (mmcblk0p2): mounted filesystem with ordered data mode. Opts: (null)
[    2.266792] EXT4-fs (mmcblk0p5): mounted filesystem with ordered data mode. Opts: (null)
[    2.571456] usb 1-1.1.1: new high-speed USB device number 5 using dwc_otg
[    2.701649] usb 1-1.1.1: New USB device found, idVendor=0424, idProduct=7800
[    2.701662] usb 1-1.1.1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
[    2.927332] EXT4-fs (mmcblk0p2): re-mounted. Opts: (null)
[    2.938229] aufs au_opts_verify:1609:init[1]: dirperm1 breaks the protection by the permission bits on the lower branch
[    3.328533] systemd[1]: System time before build time, advancing clock.
[    3.353907] systemd[1]: systemd 237 running in system mode. (-PAM -AUDIT -SELINUX +IMA -APPARMOR +SMACK +SYSVINIT +UTMP -LIBCRYPTSETUP -GCRYPT -GNUTLS +ACL +XZ -LZ4 -SECCOMP +BLKID -ELFUTILS +KMOD -IDN2 -IDN -PCRE2 default-hierarchy=hybrid)
[    3.354194] systemd[1]: Detected architecture arm.
[    3.357613] systemd[1]: No hostname configured.
[    3.357634] systemd[1]: Set hostname to <localhost>.
[    3.364958] systemd[1]: Hardware watchdog 'Broadcom BCM2835 Watchdog timer', version 0
[    3.364985] systemd[1]: Set hardware watchdog to 10s.
[    3.450237] systemd[1]: File /lib/systemd/system/systemd-journald.service:35 configures an IP firewall (IPAddressDeny=any), but the local system does not support BPF/cgroup based firewalling.
[    3.450255] systemd[1]: Proceeding WITHOUT firewalling in effect! (This warning is only shown for the first loaded unit using IP firewalling.)
[    3.626962] systemd[1]: Unnecessary job for /dev/disk/by-label/resin-state was removed.
[    3.626994] systemd[1]: Unnecessary job for /dev/disk/by-partuuid/cf17c89d-02 was removed.
[    3.632187] random: systemd: uninitialized urandom read (16 bytes read)
[    3.632485] random: systemd: uninitialized urandom read (16 bytes read)
[    3.632672] random: systemd: uninitialized urandom read (16 bytes read)
[    4.925156] snd_bcm2835: module is from the staging directory, the quality is unknown, you have been warned.
[    4.930794] bcm2835_alsa bcm2835_alsa: card created with 8 channels
[    4.992244] rtc-ds1307 1-0068: registered as rtc0
[    5.071424] libphy: lan78xx-mdiobus: probed
[    5.076836] lan78xx 1-1.1.1:1.0 (unnamed net_device) (uninitialized): int urb period 64
[    5.178537] brcmfmac: F1 signature read @0x18000000=0x15264345
[    5.188747] brcmfmac: brcmf_fw_map_chip_to_name: using brcm/brcmfmac43455-sdio.bin for chip 0x004345(17221) rev 0x000006
[    5.189589] usbcore: registered new interface driver brcmfmac
[    5.222173] usbcore: registered new interface driver lan78xx
[    5.402063] random: crng init done
[    5.402074] random: 7 urandom warning(s) missed due to ratelimiting
[    5.402494] EXT4-fs (mmcblk0p3): mounted filesystem with ordered data mode. Opts: (null)
[    5.477358] brcmfmac: brcmf_c_preinit_dcmds: Firmware version = wl0: Feb 27 2018 03:15:32 version 7.45.154 (r684107 CY) FWID 01-4fbe0b04
[    5.477763] brcmfmac: brcmf_c_preinit_dcmds: CLM version = API: 12.2 Data: 9.10.105 Compiler: 1.29.4 ClmImport: 1.36.3 Creation: 2018-03-09 18:56:28 
[    6.379684] uart-pl011 3f201000.serial: no DMA platform data
[    7.440214] i2c /dev entries driver
[    7.455584] brcmfmac: power management disabled
[    8.292412] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
[    8.295612] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
[    8.327484] IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
[    8.352996] IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
[    8.353031] brcmfmac: power management disabled
[    8.874327] IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
[    8.874376] brcmfmac: power management disabled
[    8.952321] EXT4-fs (mmcblk0p6): mounted filesystem with ordered data mode. Opts: (null)
[    9.139287] IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
[   12.834633] Bridge firewalling registered
[   12.931653] Bluetooth: Core ver 2.22
[   12.931707] NET: Registered protocol family 31
[   12.931712] Bluetooth: HCI device and connection manager initialized
[   12.931728] Bluetooth: HCI socket layer initialized
[   12.931737] Bluetooth: L2CAP socket layer initialized
[   12.931756] Bluetooth: SCO socket layer initialized
[   12.953373] Bluetooth: HCI UART driver ver 2.3
[   12.953400] Bluetooth: HCI UART protocol H4 registered
[   12.953411] Bluetooth: HCI UART protocol Three-wire (H5) registered
[   12.953667] Bluetooth: HCI UART protocol Broadcom registered
[   13.129673] Netfilter messages via NETLINK v0.30.
[   13.133761] ctnetlink v0.93: registering with nfnetlink.
[   13.242463] Bluetooth: BNEP (Ethernet Emulation) ver 1.3
[   13.242475] Bluetooth: BNEP filters: protocol multicast
[   13.242488] Bluetooth: BNEP socket layer initialized
[   13.704563] IPv6: ADDRCONF(NETDEV_UP): balena0: link is not ready
[   13.892530] IPv6: ADDRCONF(NETDEV_UP): supervisor0: link is not ready
[   14.094295] IPv6: ADDRCONF(NETDEV_UP): br-46430e63adbf: link is not ready
[   19.960326] systemd-udevd[25]: starting version 232
[   19.994622] systemd-udevd[25]: starting version 232
[   22.001951] ip6_tables: (C) 2000-2006 Netfilter Core Team
[   24.547962] usbcore: registered new interface driver usbserial
[   24.548045] usbcore: registered new interface driver usbserial_generic
[   24.548105] usbserial: USB Serial support registered for generic
[   24.555761] usbcore: registered new interface driver cp210x
[   24.555841] usbserial: USB Serial support registered for cp210x
[   24.560495] cp210x 1-1.3:1.0: cp210x converter detected
[   24.585672] usb 1-1.3: cp210x converter now attached to ttyUSB0
[  114.464519] IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
[  114.464584] brcmfmac: power management disabled
[  117.592946] IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
[  432.338445] usb 1-1.1.3: new high-speed USB device number 6 using dwc_otg
[  432.478712] usb 1-1.1.3: New USB device found, idVendor=1fc9, idProduct=0083
[  432.478725] usb 1-1.1.3: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[  432.478730] usb 1-1.1.3: Product: VCOM Port
[  432.478736] usb 1-1.1.3: Manufacturer: NXP
[  432.478742] usb 1-1.1.3: SerialNumber: NXP-77
[  432.532760] cdc_acm 1-1.1.3:1.0: ttyACM0: USB ACM device
[  432.533256] usbcore: registered new interface driver cdc_acm
[  432.533267] cdc_acm: USB Abstract Control Model driver for USB modems and ISDN adapters
11

I don’t find anything suspicious in the dmesg so please let us know when it occurs again, thank you.