<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> </head> <body> <div dir="ltr">Hi aleks, <div><br> </div> <div>Thanks for response.</div> <div>Does updating firmware to latest can be of any help?</div> <div><br> </div> <div>Pradeep G</div> </div> <span id="draft-break"></span><br> <br> ---<br> Sent from <a href="https://whatisworkspaceone.com/boxer">Workspace ONE Boxer</a><span id="draft-break"></span><br> <br> <div> <div class="null" dir="auto">On February 7, 2023 at 03:26:01 PST, Aleksander Morgado <aleksandermj@chromium.org> wrote:<br class="null"> </div> <blockquote type="cite" style="border-left-style:solid;border-width:1px;margin-left:0px;padding-left:10px;" class="null"> <div class="null" dir="auto"> <div class="null"> <meta name="Generator" content="Microsoft Exchange Server" class="null">  <div class="null"><font size="2" class="null"><span style="font-size:11pt;" class="null"> <div class="null">!! External Email<br class="null"> <br class="null"> Hey Pradeep!<br class="null"> <br class="null"> > We am seeing a strange issue where Modem instance reconnects automatically once<br class="null"> > in a while, modem used in EM7455. This happens after some time of succesful<br class="null"> > data connection and the once the issue occurs network is disrupted for 30-45 seconds.<br class="null"> > This is very random and some times happens quite often like every 1 hour or so.<br class="null"> > From the debug logs I can see there is USB disconnect and qcdm reports "unexpected port hangup" .<br class="null"> > I tried searching modemforums and issues in gitlab, but didn't find any one reporting this kind<br class="null"> > of behavior for EM7455, it would be of great help if anyone can throw some light on this failure.<br class="null"> ><br class="null"> > Logs:<br class="null"> > From logs:<br class="null"> > 2023-02-03T16:56:13.564 INFO kern kernel:[16332.259560] usb 1-1.3: USB disconnect, device number 5<br class="null"> > 2023-02-03T16:56:13.044 DEBUG daemon ModemManager[5106]: <debug> [modem0/ttyUSB0/qcdm] unexpected port hangup!<br class="null"> > 2023-02-03T16:56:13.044 DEBUG daemon ModemManager[5106]: <debug> [modem0/ttyUSB0/qcdm] forced to close port<br class="null"> > 2023-02-03T16:56:13.044 DEBUG daemon ModemManager[5106]: <debug> [modem0/ttyUSB0/qcdm] device open count is 0 (close)<br class="null"> > 2023-02-03T16:56:13.044 DEBUG daemon ModemManager[5106]: <debug> [modem0/ttyUSB0/qcdm] closing serial port<br class="null"> > 2023-02-03T16:56:13.044 DEBUG daemon ModemManager[5106]: <debug> [modem0/ttyUSB0/qcdm] serial port closed<br class="null"> > 2023-02-03T16:56:13.565 INFO kern kernel:[16332.261131] qcserial ttyUSB0: Qualcomm USB modem converter now disconnected from ttyUSB0<br class="null"> > 2023-02-03T16:56:13.566 INFO kern kernel:[16332.261629] qcserial 1-1.3:1.0: device disconnected<br class="null"> > 2023-02-03T16:56:13.567 INFO kern kernel:[16332.262427] qcserial ttyUSB1: Qualcomm USB modem converter now disconnected from ttyUSB1<br class="null"> > 2023-02-03T16:56:13.567 INFO kern kernel:[16332.262472] qcserial 1-1.3:1.2: device disconnected<br class="null"> > 2023-02-03T16:56:13.047 DEBUG daemon ModemManager[5106]: <debug> [modem0/ttyUSB2/at] unexpected port hangup!<br class="null"> > 2023-02-03T16:56:13.047 DEBUG daemon ModemManager[5106]: <debug> [modem0/ttyUSB2/at] forced to close port<br class="null"> > 2023-02-03T16:56:13.047 DEBUG daemon ModemManager[5106]: <debug> [modem0/ttyUSB2/at] device open count is 0 (close)<br class="null"> > 2023-02-03T16:56:13.047 DEBUG daemon ModemManager[5106]: <debug> [modem0/ttyUSB2/at] closing serial port...<br class="null"> > 2023-02-03T16:56:13.047 DEBUG daemon ModemManager[5106]: <debug> [modem0/ttyUSB2/at] serial port closed<br class="null"> > 2023-02-03T16:56:13.569 INFO kern kernel:[16332.264374] qcserial ttyUSB2: Qualcomm USB modem converter now disconnected from ttyUSB2<br class="null"> > 2023-02-03T16:56:13.569 INFO kern kernel:[16332.264424] qcserial 1-1.3:1.3: device disconnected 2023-02-03T16:56:13.572 INFO kern kernel:[16332.267600] qmi_wwan 1-1.3:1.8 wwan0: unregister 'qmi_wwan' usb-0000:00:16.0-1.3, WWAN/QMI device<br class="null"> > 2023-02-03T16:56:13.053 NOTICE daemon netifd: Network device 'wwan0' link is down<br class="null"> ><br class="null"> ><br class="null"> > Versions used<br class="null"> > libqmi: 1.28.6-1<br class="null"> > libmbim: 1.24.8-1<br class="null"> > modemmanager: 1.16.6.1<br class="null"> > openwrt: 19.07 based solution.<br class="null"> ><br class="null"> > Carrier : Vodafone<br class="null"> > EM7455 firmware used: "SWI9X30C_02.24.03.00 r6978 CARMD-EV-FRMWR2 2017/03/02 13:36:45<br class="null"> > response: '!IMPREF: ^M<br class="null"> > preferred fw version: 02.24.03.00^M<br class="null"> > preferred carrier name: VODAFONE^M<br class="null"> > preferred config name: VODAFONE_001.001_000^M<br class="null"> > current fw version: 02.24.03.00^M<br class="null"> > current carrier name: VODAFONE^M<br class="null"> > current config name: VODAFONE_001.001_000'<br class="null"> ><br class="null"> <br class="null"> This is a modem firmware crash; we see the device going away from the<br class="null"> USB bus and then back again after it self-resets. There is absolutely<br class="null"> nothing we can do to prevent this (unless you detect this is happening<br class="null"> due to certain configuration or something).<br class="null"> <br class="null"> If you can more or less reliably reproduce this in a controlled dev<br class="null"> environment, you could try to gather QXDM traces from the modem and<br class="null"> talk to Sierra so that they have them analyzed. You should definitely<br class="null"> involve the manufacturer in troubleshooting this.<br class="null"> <br class="null"> --<br class="null"> Aleksander<br class="null"> <br class="null"> !! External Email: This email originated from outside of the organization. Do not click links or open attachments unless you recognize the sender.<br class="null"> </div> </span></font></div> </div> </div> </blockquote> </div> </body> </html>