Hi Alan, On 1/25/20, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > On Fri, 24 Jan 2020, JH wrote: > >> Hi, >> >> I am running kernel 4.19.75 on iMX6 with a uBlox SARA-R4 LTE modem, >> the modem manager is oFono, connect manager is connman. It could >> connect to LTE between half hours to hours, then it dropped LTE >> connection randomly, here are error messages, what could cause the >> qmi_wwan status received: -71 and qmi_wwan usb_submit_urb failed with >> result -19 errors? > > The most likely cause is that the modem's firmware crashed, or it > disconnected itself electronically from the USB bus. Or else somebody > unplugged the USB cable. There is no physical USB cable to connect to the device, the device USB power supply is from its internal DC source which converted and connected from external normal AC power. If it is a USB electronic fault, the firmware is using Linux kernel USB, oFono and connman, which one could be the source to cause the crash, Linux kernel USB driver, oFono or connman? I am diagnosing the issue, I try to narrow down the source to cause the problem, is it fair to say that the higher layer software package including oFono, connman or our software applications is unlikely the source to cause the problem? Appreciate if you could advise which components could be the issue, what could be a solution to fix it. Thank you. Kind regards, - jh > Alan Stern > >> >> [ 1018.944840] usb 1-1: USB disconnect, device number 2 >> [ 1019.072845] option1 ttyUSB0: GSM modem (1-port) converter now >> disconnected from ttyUSB0 >> [ 1019.130834] option 1-1:1.0: device disconnected >> [ 1019.142012] qmi_wwan 1-1:1.3: nonzero urb status received: -71 >> [ 1019.147909] qmi_wwan 1-1:1.3: wdm_int_callback - 0 bytes >> [ 1019.153254] qmi_wwan 1-1:1.3: wdm_int_callback - usb_submit_urb >> failed with result -19 >> [ 1019.228197] option1 ttyUSB1: GSM modem (1-port) converter now >> disconnected from ttyUSB1 >> [ 1019.274475] option 1-1:1.2: device disconnected >> [ 1019.340442] qmi_wwan 1-1:1.3 wwan0: unregister 'qmi_wwan' >> usb-ci_hdrc.1-1, WWAN/QMI device >> [ 1022.827992] usb 1-1: new high-speed USB device number 3 using ci_hdrc >> [ 1023.057165] option 1-1:1.0: GSM modem (1-port) converter detected >> [ 1023.097815] usb 1-1: GSM modem (1-port) converter now attached to >> ttyUSB0 >> [ 1023.157293] option 1-1:1.2: GSM modem (1-port) converter detected >> [ 1023.178163] usb 1-1: GSM modem (1-port) converter now attached to >> ttyUSB1 >> [ 1023.201251] qmi_wwan 1-1:1.3: cdc-wdm0: USB WDM device >> [ 1023.243783] qmi_wwan 1-1:1.3 wwan0: register 'qmi_wwan' at >> usb-ci_hdrc.1-1, WWAN/QMI device, 16:ed:38:aa:c5:90 >> >> Thank you. >> >> Kind regards, >> >> - jh > >
