ECM模式下能够正常识别usb网口和串口，但连接过一会就会断开重新识别usb设备。
5G模块的供电如果是USB Dongle一般供电是不够的。
这个怎么能确定一下是供电不够导致的吗？
可以提供下对应的内核日志看看，看看断开和重连的时间差多少。
[ 12.918440] usb 1-1: new high-speed USB device number 3 using ehci-platform
[ 13.067295] usb 1-1: New USB device found, idVendor=1782, idProduct=4d00, bcdDevice=24.30
[ 13.067379] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[ 13.067407] usb 1-1: Product: Gadget Serial
[ 13.067433] usb 1-1: Manufacturer: spreadtrum with dwc3-gadget
[ 13.072388] [I/USB_PNP_NOTIFY] UsbPnpNotifyCallback: action=0x1\x0d
[ 13.072414] [I/USB_PNP_NOTIFY] UsbPnpNotifyAddInitInfo:209 i=0, interfaceInfo=0xff-0x0-0x0-0x0\x0d
[ 13.072436] [I/USB_PNP_NOTIFY] UsbPnpNotifyReportThread: UsbPnpNotifyReportThread start!\x0d
[ 13.072451] [I/USB_PNP_NOTIFY] UsbPnpNotifyHdfSendEvent:375 device information, 3 usbDevAddr=18446743528310282240, devNum=3, busNum=1, infoTable=1-0x1782-0x4d00!\x0d
[ 13.327487] binder: release 1355:1355 transaction 18904 out, still active
[ 13.327520] binder: undelivered TRANSACTION_COMPLETE
[ 13.329754] binder_transaction: 8952 callbacks suppressed
[ 13.329759] binder: 624:1152 transaction failed 29189/0, size 4-0 line 3222
[ 13.329776] binder: send failed reply for transaction 18904, target dead
[ 17.829793] [pid=1][PARAM][INFO][param_service.c:173]Handle set param msgId 4 pid 624 key: startup.service.ctl.broker
[ 19.590211] usb 1-1: USB disconnect, device number 3
[ 19.592236] [I/USB_PNP_NOTIFY] UsbPnpNotifyCallback: action=0x2\x0d
[ 19.592343] [I/USB_PNP_NOTIFY] UsbPnpNotifyReportThread: UsbPnpNotifyReportThread start!\x0d
[ 19.592360] [I/USB_PNP_NOTIFY] UsbPnpNotifyHdfSendEvent:375 device information, 4 usbDevAddr=18446743528310282240, devNum=3, busNum=1, infoTable=1-0x1782-0x4d00!\x0d
[ 19.592723] [pid=245][ueventd][INFO][ueventd_device_handler.c:224]unlink /dev/bus/usb/001/003
[ 25.305245] usb 1-1: new high-speed USB device number 4 using ehci-platform
[ 25.454686] usb 1-1: New USB device found, idVendor=2c7c, idProduct=0900, bcdDevice= 4.04
[ 25.454757] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 25.454786] usb 1-1: Product: RM500U-CNV
[ 25.454812] usb 1-1: Manufacturer: Quectel
[ 25.454838] usb 1-1: SerialNumber: 0123456789ABCDEF
[ 25.462076] [dhd] CFG80211-ERROR) wl_cfg80211_netdev_notifier_call : wdev null. Do nothing
[ 25.464701] [dhd] CFG80211-ERROR) wl_cfg80211_netdev_notifier_call : wdev null. Do nothing
[ 25.465027] cdc_ether 1-1:1.0 usb0: register ‘cdc_ether’ at usb-fc800000.usb-1, CDC Ethernet Device, ae:1f:8d:6a:c5:19
[ 25.465466] [dhd] CFG80211-ERROR) wl_cfg80211_netdev_notifier_call : wdev null. Do nothing
[ 25.465898] [dhd] CFG80211-ERROR) wl_cfg80211_netdev_notifier_call : wdev null. Do nothing
[ 25.479090] option 1-1:1.2: GSM modem (1-port) converter detected
[ 25.480432] [dhd] CFG80211-ERROR) wl_cfg80211_netdev_notifier_call : wdev null. Do nothing
[ 25.480717] usb 1-1: GSM modem (1-port) converter now attached to ttyUSB0
[ 25.482076] option 1-1:1.3: GSM modem (1-port) converter detected
[ 25.482407] usb 1-1: GSM modem (1-port) converter now attached to ttyUSB1
[ 25.482813] option 1-1:1.4: GSM modem (1-port) converter detected
[ 25.483377] usb 1-1: GSM modem (1-port) converter now attached to ttyUSB2
[ 25.483771] option 1-1:1.5: GSM modem (1-port) converter detected
[ 25.484020] usb 1-1: GSM modem (1-port) converter now attached to ttyUSB3
[ 25.484304] option 1-1:1.6: GSM modem (1-port) converter detected
[ 25.484538] usb 1-1: GSM modem (1-port) converter now attached to ttyUSB4
[ 25.484707] [I/USB_PNP_NOTIFY] UsbPnpNotifyCallback: action=0x1\x0d
[ 25.484719] [I/USB_PNP_NOTIFY] UsbPnpNotifyAddInitInfo:209 i=0, interfaceInfo=0x2-0x6-0x0-0x0\x0d
[ 25.484727] [I/USB_PNP_NOTIFY] UsbPnpNotifyAddInitInfo:209 i=1, interfaceInfo=0xa-0x0-0x0-0x1\x0d
[ 25.484734] [I/USB_PNP_NOTIFY] UsbPnpNotifyAddInitInfo:209 i=2, interfaceInfo=0xff-0x0-0x0-0x2\x0d
[ 25.484741] [I/USB_PNP_NOTIFY] UsbPnpNotifyAddInitInfo:209 i=3, interfaceInfo=0xff-0x0-0x0-0x3\x0d
[ 25.484748] [I/USB_PNP_NOTIFY] UsbPnpNotifyAddInitInfo:209 i=4, interfaceInfo=0xff-0x0-0x0-0x4\x0d
[ 25.484755] [I/USB_PNP_NOTIFY] UsbPnpNotifyAddInitInfo:209 i=5, interfaceInfo=0xff-0x0-0x0-0x5\x0d
[ 25.484761] [I/USB_PNP_NOTIFY] UsbPnpNotifyAddInitInfo:209 i=6, interfaceInfo=0xff-0x0-0x0-0x6\x0d
[ 25.484784] [I/USB_PNP_NOTIFY] UsbPnpNotifyReportThread: UsbPnpNotifyReportThread start!\x0d
[ 25.484800] [I/USB_PNP_NOTIFY] UsbPnpNotifyHdfSendEvent:375 device information, 3 usbDevAddr=18446743529089957888, devNum=4, busNum=1, infoTable=7-0x2c7c-0x900!\x0d
[ 25.497397] [pid=1][Init][ERROR][init_signal_handler.c:47]Child process Unknown(pid 1458) exit with code : 0
[ 25.497410] [pid=1][Init][INFO][init_signal_handler.c:56]SigHandler, SIGCHLD received, Service:Unknown pid:1458 uid:1099 status:0.
[ 25.603396] [pid=1][Init][ERROR][init_signal_handler.c:47]Child process Unknown(pid 1459) exit with code : 0
[ 25.603471] [pid=1][Init][INFO][init_signal_handler.c:56]SigHandler, SIGCHLD received, Service:Unknown pid:1459 uid:1099 status:0.
[ 36.287480] [pid=255][PLUGIN][INFO][init_context.c:235]Poll sub init timeout, sub init 0 exit
[ 36.289426] [pid=1][Init][ERROR][init_signal_handler.c:47]Child process Unknown(pid 255) exit with code : 127
[ 36.289601] [pid=1][Init][INFO][init_signal_handler.c:56]SigHandler, SIGCHLD received, Service:Unknown pid:255 uid:0 status:32512.
[ 36.959427] [dhd] CFG80211-ERROR) wl_cfg80211_netdev_notifier_call : wdev null. Do nothing
[ 37.003785] [pid=1][Init][ERROR][init_signal_handler.c:47]Child process Unknown(pid 1466) exit with code : 0
[ 37.003808] [pid=1][Init][INFO][init_signal_handler.c:56]SigHandler, SIGCHLD received, Service:Unknown pid:1466 uid:1099 status:0.
[ 40.549496] [pid=1][PARAM][INFO][param_service.c:173]Handle set param msgId 8 pid 263 key: ohos.ctl.start
[ 40.549595] [pid=1][Init][INFO][init_service_manager.c:1088]Start service devattest_service|5501#4#usual.event.CONNECTIVITY_CHANGE#3#8#
[ 40.550020] [pid=1][Init][INFO][init_common_service.c:567]Service devattest_service(pid 1474) started
[ 42.318291] [pid=1][PARAM][INFO][param_service.c:173]Handle set param msgId 2 pid 1474 key: persist.xts.devattest.authresult
[ 42.326002] [pid=1][Init][ERROR][init_signal_handler.c:44]Child process devattest_service(pid 1474) exit with signal : 9
[ 42.326058] [pid=1][Init][INFO][init_signal_handler.c:56]SigHandler, SIGCHLD received, Service:devattest_service pid:1474 uid:3049 status:9.
[ 42.326080] [pid=1][Init][INFO][init_common_service.c:688]Reap service devattest_service, pid 1474.
[ 66.006071] [pid=245][ueventd][INFO][ueventd_main.c:39]poll ueventd socket timeout, ueventd exit
[ 66.007912] [pid=1][Init][ERROR][init_signal_handler.c:47]Child process ueventd(pid 245) exit with code : 0
[ 66.008017] [pid=1][Init][INFO][init_signal_handler.c:56]SigHandler, SIGCHLD received, Service:ueventd pid:245 uid:1004 status:0.
[ 66.008062] [pid=1][Init][INFO][init_common_service.c:688]Reap service ueventd, pid 245.
[ 66.008559] [pid=1][Init][INFO][init_service_socket.c:195]Watcher socket fd 13 for service ueventd
[ 75.785742] usb 1-1: USB disconnect, device number 4
[ 75.788417] cdc_ether 1-1:1.0 usb0: unregister ‘cdc_ether’ usb-fc800000.usb-1, CDC Ethernet Device
[ 75.788448] [dhd] CFG80211-ERROR) wl_cfg80211_netdev_notifier_call : wdev null. Do nothing
[ 75.789269] [dhd] CFG80211-ERROR) wl_cfg80211_netdev_notifier_call : wdev null. Do nothing
[ 75.789552] [dhd] CFG80211-ERROR) wl_cfg80211_netdev_notifier_call : wdev null. Do nothing
[ 75.789754] [pid=1][Init][INFO][init_service_socket.c:179]Socket information detected, fd:13 service name:ueventd
[ 75.790177] [pid=1][Init][INFO][init_common_service.c:567]Service ueventd(pid 1500) started
[ 75.798852] [pid=1500][ueventd][INFO][ueventd_main.c:97]ueventd start to process uevent message
[ 75.806019] option1 ttyUSB0: GSM modem (1-port) converter now disconnected from ttyUSB0
[ 75.806039] [pid=1500][ueventd][INFO][ueventd_device_handler.c:224]unlink /dev/ttyUSB0
[ 75.806148] option 1-1:1.2: device disconnected
[ 75.806747] [pid=1500][ueventd][INFO][ueventd_device_handler.c:224]unlink /dev/ttyUSB1
[ 75.806778] option1 ttyUSB1: GSM modem (1-port) converter now disconnected from ttyUSB1
[ 75.806961] option 1-1:1.3: device disconnected
[ 75.807519] [pid=1500][ueventd][INFO][ueventd_device_handler.c:224]unlink /dev/ttyUSB2
[ 75.807561] option1 ttyUSB2: GSM modem (1-port) converter now disconnected from ttyUSB2
[ 75.807778] option 1-1:1.4: device disconnected
[ 75.808763] option1 ttyUSB3: GSM modem (1-port) converter now disconnected from ttyUSB3
[ 75.808914] option 1-1:1.5: device disconnected
[ 75.809028] [pid=1500][ueventd][INFO][ueventd_device_handler.c:224]unlink /dev/ttyUSB3
[ 75.809564] [pid=1][Init][ERROR][init_signal_handler.c:47]Child process Unknown(pid 1467) exit with code : 0
[ 75.809580] [pid=1][Init][INFO][init_signal_handler.c:56]SigHandler, SIGCHLD received, Service:Unknown pid:1467 uid:1099 status:0.
[ 75.809633] [pid=1500][ueventd][INFO][ueventd_device_handler.c:224]unlink /dev/ttyUSB4
[ 75.809695] option1 ttyUSB4: GSM modem (1-port) converter now disconnected from ttyUSB4
[ 75.809795] option 1-1:1.6: device disconnected
[ 75.810182] [I/USB_PNP_NOTIFY] UsbPnpNotifyCallback: action=0x2\x0d
[ 75.810203] [I/USB_PNP_NOTIFY] UsbPnpNotifyReportThread: UsbPnpNotifyReportThread start!\x0d
[ 75.810219] [I/USB_PNP_NOTIFY] UsbPnpNotifyHdfSendEvent:375 device information, 4 usbDevAddr=18446743529089957888, devNum=4, busNum=1, infoTable=7-0x2c7c-0x900!\x0d
[ 75.810401] [pid=1500][ueventd][INFO][ueventd_device_handler.c:224]unlink /dev/bus/usb/001/004
[ 80.511884] usb 1-1: new high-speed USB device number 5 using ehci-platform
[ 80.660670] usb 1-1: New USB device found, idVendor=1782, idProduct=4d00, bcdDevice=24.30
[ 80.660755] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[ 80.660783] usb 1-1: Product: Gadget Serial
[ 80.660809] usb 1-1: Manufacturer: spreadtrum with dwc3-gadget
[ 80.667415] [I/USB_PNP_NOTIFY] UsbPnpNotifyCallback: action=0x1\x0d
[ 80.667506] [I/USB_PNP_NOTIFY] UsbPnpNotifyAddInitInfo:209 i=0, interfaceInfo=0xff-0x0-0x0-0x0\x0d
[ 80.667705] [I/USB_PNP_NOTIFY] UsbPnpNotifyReportThread: UsbPnpNotifyReportThread start!\x0d
[ 80.667773] [I/USB_PNP_NOTIFY] UsbPnpNotifyHdfSendEvent:375 device information, 3 usbDevAddr=18446743529034985472, devNum=5, busNum=1, infoTable=1-0x1782-0x4d00!\x0d
[ 87.178202] usb 1-1: USB disconnect, device number 5
[ 87.180364] [I/USB_PNP_NOTIFY] UsbPnpNotifyCallback: action=0x2\x0d
[ 87.180447] [I/USB_PNP_NOTIFY] UsbPnpNotifyReportThread: UsbPnpNotifyReportThread start!\x0d
[ 87.180465] [I/USB_PNP_NOTIFY] UsbPnpNotifyHdfSendEvent:375 device information, 4 usbDevAddr=18446743529034985472, devNum=5, busNum=1, infoTable=1-0x1782-0x4d00!\x0d
[ 87.180606] [pid=1500][ueventd][INFO][ueventd_device_handler.c:224]unlink /dev/bus/usb/001/005
[ 93.091806] usb 1-1: new high-speed USB device number 6 using ehci-platform
[ 93.241075] usb 1-1: New USB device found, idVendor=2c7c, idProduct=0900, bcdDevice= 4.04
[ 93.241148] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 93.241177] usb 1-1: Product: RM500U-CNV
[ 93.241203] usb 1-1: Manufacturer: Quectel
[ 93.241228] usb 1-1: SerialNumber: 0123456789ABCDEF
[ 93.247743] [dhd] CFG80211-ERROR) wl_cfg80211_netdev_notifier_call : wdev null. Do nothing
[ 93.251760] [dhd] CFG80211-ERROR) wl_cfg80211_netdev_notifier_call : wdev null. Do nothing
[ 93.251991] cdc_ether 1-1:1.0 usb0: register ‘cdc_ether’ at usb-fc800000.usb-1, CDC Ethernet Device, fa
6a:c1:54:dc
[ 93.253412] option 1-1:1.2: GSM modem (1-port) converter detected
[ 93.254206] [dhd] CFG80211-ERROR) wl_cfg80211_netdev_notifier_call : wdev null. Do nothing
[ 93.254633] [dhd] CFG80211-ERROR) wl_cfg80211_netdev_notifier_call : wdev null. Do nothing
[ 93.255341] usb 1-1: GSM modem (1-port) converter now attached to ttyUSB0
[ 93.260541] option 1-1:1.3: GSM modem (1-port) converter detected
[ 93.262659] usb 1-1: GSM modem (1-port) converter now attached to ttyUSB1
[ 93.263723] option 1-1:1.4: GSM modem (1-port) converter detected
[ 93.264931] usb 1-1: GSM modem (1-port) converter now attached to ttyUSB2
[ 93.266454] option 1-1:1.5: GSM modem (1-port) converter detected
[ 93.267293] usb 1-1: GSM modem (1-port) converter now attached to ttyUSB3
[ 93.268469] option 1-1:1.6: GSM modem (1-port) converter detected
[ 93.269322] usb 1-1: GSM modem (1-port) converter now attached to ttyUSB4
[ 93.269994] [I/USB_PNP_NOTIFY] UsbPnpNotifyCallback: action=0x1\x0d
[ 93.270011] [I/USB_PNP_NOTIFY] UsbPnpNotifyAddInitInfo:209 i=0, interfaceInfo=0x2-0x6-0x0-0x0\x0d
[ 93.270021] [I/USB_PNP_NOTIFY] UsbPnpNotifyAddInitInfo:209 i=1, interfaceInfo=0xa-0x0-0x0-0x1\x0d
[ 93.270031] [I/USB_PNP_NOTIFY] UsbPnpNotifyAddInitInfo:209 i=2, interfaceInfo=0xff-0x0-0x0-0x2\x0d
[ 93.270041] [I/USB_PNP_NOTIFY] UsbPnpNotifyAddInitInfo:209 i=3, interfaceInfo=0xff-0x0-0x0-0x3\x0d
[ 93.270050] [I/USB_PNP_NOTIFY] UsbPnpNotifyAddInitInfo:209 i=4, interfaceInfo=0xff-0x0-0x0-0x4\x0d
[ 93.270059] [I/USB_PNP_NOTIFY] UsbPnpNotifyAddInitInfo:209 i=5, interfaceInfo=0xff-0x0-0x0-0x5\x0d
[ 93.270069] [I/USB_PNP_NOTIFY] UsbPnpNotifyAddInitInfo:209 i=6, interfaceInfo=0xff-0x0-0x0-0x6\x0d
[ 93.270206] [I/USB_PNP_NOTIFY] UsbPnpNotifyReportThread: UsbPnpNotifyReportThread start!\x0d
[ 93.270231] [I/USB_PNP_NOTIFY] UsbPnpNotifyHdfSendEvent:375 device information, 3 usbDevAddr=18446743529034981376, devNum=6, busNum=1, infoTable=7-0x2c7c-0x900!\x0d
[ 93.285669] [dhd] CFG80211-ERROR) wl_cfg80211_netdev_notifier_call : wdev null. Do nothing
[ 93.298626] [pid=1][Init][ERROR][init_signal_handler.c:47]Child process Unknown(pid 1558) exit with code : 0
[ 93.298640] [pid=1][Init][INFO][init_signal_handler.c:56]SigHandler, SIGCHLD received, Service:Unknown pid:1558 uid:1099 status:0.
[ 93.406997] [pid=1][Init][ERROR][init_signal_handler.c:47]Child process Unknown(pid 1559) exit with code : 0
从这个日志几乎可以肯定模组是重启了。usb dongle 供电不够的。
你可以用示波器抓下电源有关的波形看看。