I am using a Nova410 on a Pi4 running Raspian Buster that I was finally able to apply the firmware update to. After the firmware update I am encountering frequent “Unable to detect serial port” issues. Sometimes both ttyUSB0 and ttyUSB1 are available, sometimes ttyUSB1 is missing. lsof shows no processes using either port. I have been able to successfully connect once but most other times have been met with failure. Even when I have not been able to establish a connection, the hologram dashboard reports that it is in fact connected and data is being used despite there being no ppp device active or connection created. I have tried multiple power supplies with the same result. It feels as if there is a software conflict though no modem manager is installed and this configuration was working well prior to the firmware update. Any advice on how to proceed would be appreciated.
[ 57.290380] PPP generic driver version 2.4.2
[ 60.893183] PPP BSD Compression module registered
[ 60.903637] PPP Deflate Compression module registered
[ 119.031685] ------------[ cut here ]------------
[ 119.031728] WARNING: CPU: 1 PID: 0 at net/sched/sch_generic.c:466 dev_watchdog+0x294/0x298
[ 119.031745] NETDEV WATCHDOG: wwan0 (qmi_wwan): transmit queue 0 timed out
[ 119.031759] Modules linked in: ppp_deflate zlib_deflate bsd_comp ppp_async crc_ccitt ppp_generic slhc bnep hci_uart btbcm serdev bluetooth ecdh_generic 8021q garp stp llc option usb_wwan qmi_wwan usbserial cdc_wdm bcm2835_codec(C) v4l2_mem2mem bcm2835_v4l2(C) bcm2835_mmal_vchiq(C) v4l2_common videobuf2_dma_contig videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_common brcmfmac videodev media brcmutil rpivid_mem vc_sm_cma(C) vc4 sha256_generic v3d drm_kms_helper gpu_sched cfg80211 rfkill drm snd_soc_core raspberrypi_hwmon snd_bcm2835(C) drm_panel_orientation_quirks hwmon snd_compress snd_pcm_dmaengine syscopyarea sysfillrect snd_pcm sysimgblt fb_sys_fops snd_timer snd uio_pdrv_genirq uio fixed sg ip_tables x_tables ipv6
[ 119.032663] CPU: 1 PID: 0 Comm: swapper/1 Tainted: G C 4.19.75-v7l+ #1270
[ 119.032671] Hardware name: BCM2835
[ 119.032698] [<c0212d10>] (unwind_backtrace) from [<c020d530>] (show_stack+0x20/0x24)
[ 119.032716] [<c020d530>] (show_stack) from [<c097fb20>] (dump_stack+0xd4/0x118)
[ 119.032736] [<c097fb20>] (dump_stack) from [<c0222330>] (__warn+0x104/0x11c)
[ 119.032753] [<c0222330>] (__warn) from [<c02223a0>] (warn_slowpath_fmt+0x58/0x74)
[ 119.032771] [<c02223a0>] (warn_slowpath_fmt) from [<c08a674c>] (dev_watchdog+0x294/0x298)
[ 119.032793] [<c08a674c>] (dev_watchdog) from [<c029a6a4>] (call_timer_fn+0x3c/0x198)
[ 119.032810] [<c029a6a4>] (call_timer_fn) from [<c029a8ec>] (expire_timers+0xec/0x14c)
[ 119.032825] [<c029a8ec>] (expire_timers) from [<c029aa04>] (run_timer_softirq+0xb8/0x1ec)
[ 119.032842] [<c029aa04>] (run_timer_softirq) from [<c0202410>] (__do_softirq+0x190/0x3f0)
[ 119.032858] [<c0202410>] (__do_softirq) from [<c0228308>] (irq_exit+0xfc/0x120)
[ 119.032879] [<c0228308>] (irq_exit) from [<c0280e08>] (__handle_domain_irq+0x70/0xc4)
[ 119.032897] [<c0280e08>] (__handle_domain_irq) from [<c0202244>] (gic_handle_irq+0x4c/0x88)
[ 119.032912] [<c0202244>] (gic_handle_irq) from [<c02019bc>] (__irq_svc+0x5c/0x7c)
[ 119.032922] Exception stack(0xef927f38 to 0xef927f80)
[ 119.032931] 7f20: c0209a84 00000000
[ 119.032944] 7f40: 40000093 40000093 c1004dbc ef926000 c1004e04 00000002 c109641a 410fd083
[ 119.032956] 7f60: 00000000 ef927f94 c10051c4 ef927f88 00000000 c0209a88 40000013 ffffffff
[ 119.032974] [<c02019bc>] (__irq_svc) from [<c0209a88>] (arch_cpu_idle+0x34/0x4c)
[ 119.032991] [<c0209a88>] (arch_cpu_idle) from [<c099cd2c>] (default_idle_call+0x34/0x48)
[ 119.033009] [<c099cd2c>] (default_idle_call) from [<c02542b4>] (do_idle+0xec/0x17c)
[ 119.033028] [<c02542b4>] (do_idle) from [<c0254604>] (cpu_startup_entry+0x28/0x2c)
[ 119.033046] [<c0254604>] (cpu_startup_entry) from [<c0210b2c>] (secondary_start_kernel+0x13c/0x148)
[ 119.033061] [<c0210b2c>] (secondary_start_kernel) from [<0020270c>] (0x20270c)
[ 119.033077] ---[ end trace b98ff601f837dfed ]---
[ 119.155045] usb 1-1.3: USB disconnect, device number 3
[ 119.155713] option1 ttyUSB0: GSM modem (1-port) converter now disconnected from ttyUSB0
[ 119.155816] option 1-1.3:1.0: device disconnected
[ 119.156704] option1 ttyUSB1: GSM modem (1-port) converter now disconnected from ttyUSB1
[ 119.156804] option 1-1.3:1.2: device disconnected
[ 119.157174] qmi_wwan 1-1.3:1.3 wwan0: unregister 'qmi_wwan' usb-0000:01:00.0-1.3, WWAN/QMI device
[ 120.091755] usb 1-1.3: new high-speed USB device number 4 using xhci_hcd
[ 120.222643] usb 1-1.3: New USB device found, idVendor=05c6, idProduct=90b2, bcdDevice= 0.00
[ 120.222660] usb 1-1.3: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 120.222673] usb 1-1.3: Product: QHSUSB__BULK
[ 120.222685] usb 1-1.3: Manufacturer: Qualcomm CDMA Technologies MSM
[ 120.222697] usb 1-1.3: SerialNumber: fbb46ee4
[ 120.226862] option 1-1.3:1.0: GSM modem (1-port) converter detected
[ 120.227175] usb 1-1.3: GSM modem (1-port) converter now attached to ttyUSB0
pi@weatherpi ~/> sudo hologram modem reset -vv
DEBUG: checking for vid_pid: ('12d1', '1001')
DEBUG: checking for vid_pid: ('12d1', '1506')
DEBUG: checking for vid_pid: ('1546', '1102')
DEBUG: checking for vid_pid: ('1546', '1104')
DEBUG: checking for vid_pid: ('05c6', '90b2')
INFO: Detected modem NovaM
DEBUG: checking port ttyUSB0
DEBUG: checking port ttyUSB1
DEBUG: [AT]
ERROR: Unable to detect a usable serial port
pi@weatherpi ~/> python test.py
PORT NAME: /dev/ttyUSB1 DESCRIPTION: Qualcomm CDMA Technologies MSM HWID: USB VID:PID=05C6:90B2 SER=fbb46ee4 LOCATION=1-1.1:1.2
PORT NAME: /dev/ttyUSB0 DESCRIPTION: Qualcomm CDMA Technologies MSM HWID: USB VID:PID=05C6:90B2 SER=fbb46ee4 LOCATION=1-1.1:1.0
PORT NAME: /dev/ttyAMA0 DESCRIPTION: ttyAMA0 HWID: fe201000.serial