<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> </head> <body> <div dir="ltr"> <div dir="ltr"> <div dir="ltr" data-ogsc="" style=""> <div dir="ltr"> <div dir="ltr" data-ogsc="" style=""> <div></div> <div> <div> <div dir="ltr" style="text-align: left;"></div> </div> <div>> Would you be able to <span style="font-size: 1rem;">draft a MM patch doing that?</span></div> <div dir="ltr" style="text-align: left;"><span style="font-size: 1rem;"><br> </span></div> <div dir="ltr" style="text-align: left;"><span style="font-size: 1rem;">Well-l-l...</span></div> <div dir="ltr" style="text-align: left;"><span style="font-size: 1rem;"><br> </span></div> <div dir="ltr" style="text-align: left;"><span style="font-size: 1rem;">I like to be challenged. Last time I coded in C is 20 years ago and I never contributed to open source. I might check out the sources and try to understand some basics over the next weeks, but cannot promise anything.</span></div> <div dir="ltr" style="text-align: left;"><span style="font-size: 1rem;"><br> </span></div> <div dir="ltr" style="text-align: left;"><span style="font-size: 1rem;">Apart from that: I had reproduced the issue with disappearing modem about 10 times now. I was always able to recover by issuing</span></div> <div dir="ltr" style="text-align: left;"><span style="font-size: 1rem;"><br> </span></div> <div dir="ltr" style="text-align: left;"><span style="font-size: 1rem;">systemctl restart ModemManager.service</span></div> <div dir="ltr" style="text-align: left;"><span style="font-size: 1rem;"><br> </span></div> <div dir="ltr" style="text-align: left;"><span style="font-size: 1rem;">and everything worked fine. I also had the impression that the primary port had somehow recovered by then.</span></div> <div dir="ltr" style="text-align: left;"><span style="font-size: 1rem;"><br> </span></div> <div dir="ltr" style="text-align: left;"><span style="font-size: 1rem;">One more question:</span></div> <div dir="ltr" style="text-align: left;"><span style="font-size: 1rem;">I found the following in the Huawei doc. When you talk about primary/secondary port, are we actually talking about Modem port/Uart port? Are they exchangeable?</span></div> <div dir="ltr" style="text-align: left;"><span style="font-size: 1rem;"><br> </span></div> <div dir="ltr" style="text-align: left;"><span style="font-size: 1rem;">...</span></div> <div dir="ltr" style="text-align: left;"><span style="font-size: 1rem;">The ME909s provides four ports to interact with its host:</span></div> <div dir="ltr" style="text-align: left;"><span style="font-size: 1rem;"> MODEM port: simulated using USB, for AT command interaction and establishing data connection.</span></div> <div dir="ltr" style="text-align: left;"><span style="font-size: 1rem;">Port name: HUAWEI Mobile Connect-3G Modem</span></div> <div dir="ltr" style="text-align: left;"><span style="font-size: 1rem;"> PCUI port: simulated using USB, for AT command interaction only.</span></div> <div dir="ltr" style="text-align: left;"><span style="font-size: 1rem;">Port name: HUAWEI Mobile Connect-3G PCUI Interface</span></div> <div dir="ltr" style="text-align: left;"><span style="font-size: 1rem;"> UART port: physical serial port, for AT command interaction and establishing data connection.</span></div> <div dir="ltr" style="text-align: left;"><span style="font-size: 1rem;"> ECM port: simulated using USB, for establishing communication connection. Port name: CDC Ethernet Control Model (ECM)</span></div> <div dir="ltr" style="text-align: left;"><span style="font-size: 1rem;">The ME909s also provides a port for debugging:</span></div> <div dir="ltr" style="text-align: left;"><span style="font-size: 1rem;"> DIAG port: simulated using USB, for DIAG (diagnostic) command interaction (mainly used to debug modules at present).</span></div> </div> </div> </div> </div> </div> </div> <hr style="display:inline-block;width:98%" tabindex="-1"> <div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>Von:</b> Aleksander Morgado <aleksander@aleksander.es><br> <b>Gesendet:</b> Wednesday, December 18, 2019 6:54:20 PM<br> <b>An:</b> Bruno Vetter <bruno.vetter@outlook.com><br> <b>Cc:</b> modemmanager-devel@lists.freedesktop.org <modemmanager-devel@lists.freedesktop.org><br> <b>Betreff:</b> Re: Huawei ME909s-120 modem goes offline and disappears</font> <div> </div> </div> <div class="BodyFragment"><font size="2"><span style="font-size:11pt;"> <div class="PlainText">> > No idea what else to do to solve this I'm afraid... :/ Maybe we could<br> > > extend the logic and add some automatic recovery mechanism to reset<br> > > the modem using the secondary port if we end up seeing that the<br> > > primary port is stuck like that? That wouldn't be ideal, but I assume<br> > > it's better to have one modem reset than having MM flag the modem as<br> > > failed.<br> ><br> > I am afraid I cannot give a suggestion here. I am just an MM user. Could you offer some advice for me how to work around the issue?<br> > We are dealing with a fleet of edge devices with a GSM only connection. So it is crucial for them to recover after such an issue.<br> > I could implement a watchdog service that detects the issue and resolves it. The question is how to detect and how to resolve.<br> > Without any further knowledge I could:<br> ><br> > Detect the issue by frequently executing mmcli -L to see if the modem has disappeared<br> > Resolve it by restarting the ModemManager service.<br> ><br> > Does that sound reasonable? If there is a more elegant way to do it please let me know.<br> ><br> <br> I assume the issue is "solved" by restarting ModemManager just because<br> we end up using the previously secondary TTY as primary, but if that<br> gets also stuck, you may end up with the device completely stuck.<br> <br> A better approach would be to detect that the primary control port is<br> stuck, and if there is a valid secondary port, try to run a modem<br> reset automatically using that secondary port. Would you be able to<br> draft a MM patch doing that?<br> <br> -- <br> Aleksander<br> <a href="https://eur04.safelinks.protection.outlook.com/?url=https%3A%2F%2Faleksander.es&data=02%7C01%7C%7Cc1433d0f8b96445ac06c08d783e35622%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637122884726105702&sdata=HcaGfa2b4QYiUTczqamkP%2FUuiYStD5rThv6JFaYjbh4%3D&reserved=0">https://eur04.safelinks.protection.outlook.com/?url=https%3A%2F%2Faleksander.es&data=02%7C01%7C%7Cc1433d0f8b96445ac06c08d783e35622%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637122884726105702&sdata=HcaGfa2b4QYiUTczqamkP%2FUuiYStD5rThv6JFaYjbh4%3D&reserved=0</a><br> </div> </span></font></div> </body> </html>