<div dir="ltr"><div>Hi,</div><div><br></div><div>I'm connected to a modem with a *single* serial port (Simcom SIM5320A with the USB port unwired)<br></div><div><br></div><div>I can connect to Internet using the old way (writing my own chat scripts). But I couldn't do it using modemmanager. I have a lot of error messages from ModemManeger like that:</div><div><br></div><div></div><div>"Couldn't refresh signal quality: 'No AT port available to run command'"</div><div><br></div><div>Can ModemManager work with a single physical UART port? any guide here?</div><div><br></div><div>Below I share more information about the issue</div><div><br></div><div>Best regards,<br></div><div><br></div><div> Andres Calderon</div><div><br></div><div><br></div><div>=================================================</div><div># udevadm info /dev/ttyAMA0<br></div><div><br></div><div>P: /devices/platform/soc/3f201000.serial/tty/ttyAMA0<br>N: ttyAMA0<br>L: 0<br>S: serial0<br>E: DEVPATH=/devices/platform/soc/3f201000.serial/tty/ttyAMA0<br>E: DEVNAME=/dev/ttyAMA0<br>E: MAJOR=204<br>E: MINOR=64<br>E: SUBSYSTEM=tty<br>E: USEC_INITIALIZED=5122363<br>E: ID_MM_CANDIDATE=1<br>E: ID_MM_TTY_FLOW_CONTROL=none<br>E: ID_MM_TTY_BAUDRATE=115200<br>E: ID_MM_DEVICE_PROCESS=1<br>E: ID_MM_PLATFORM_DRIVER_PROBE=1<br>E: DEVLINKS=/dev/serial0<br>E: TAGS=:systemd:</div><div><br></div><div>=================================================</div><div># mmcli -m 0<br> --------------------------<br> General | dbus path: /org/freedesktop/ModemManager1/Modem/0<br> | device id: 23b798cdd09c78be14e231127c48d70f5307a48e<br> --------------------------<br> Hardware | manufacturer: SIMCOM INCORPORATED<br> | model: SIMCOM_SIM5320A<br> | revision: 1575B13SIM5320A<br> | supported: gsm-umts<br> | current: gsm-umts<br> | equipment id: 012813008537617<br> --------------------------<br> System | device: /sys/devices/platform/soc<br> | drivers: uart-pl011<br> | plugin: Generic<br> | primary port: ttyAMA0<br> | ports: ttyAMA0 (at)<br> --------------------------<br> Numbers | own: +573176760667<br> --------------------------<br> Status | unlock retries: sim-pin (3), sim-pin2 (3), sim-puk (10), sim-puk2 (10)<br> | state: disabled<br> | power state: on<br> | signal quality: 0% (cached)<br> --------------------------<br> Modes | supported: allowed: 2g, 3g; preferred: none<br> | current: allowed: 2g, 3g; preferred: none<br> --------------------------<br> IP | supported: ipv4, ipv6<br> --------------------------<br> 3GPP | imei: 012813008537617<br> --------------------------</div><div><br></div><div><br></div><div><div> Andrés Calderón</div><div><br></div><div><br></div><div>====================MODEMMANAGER LOG====================<br></div></div><div>ModemManager[1133]: <debug> [1574094017.402205] No specific IP family requested, defaulting to ipv4<br>ModemManager[1133]: <debug> [1574094017.402298] No specific IP family requested, defaulting to ipv4<br>ModemManager[1133]: <debug> [1574094017.402439] Looking for best CID...<br>ModemManager[1133]: <debug> [1574094017.402551] (ttyAMA0) device open count is 6 (open)<br>ModemManager[1133]: <debug> [1574094017.402722] (ttyAMA0) device open count is 5 (close)<br>ModemManager[1133]: <debug> [1574094017.402865] (ttyAMA0): --> 'AT+COPS=3,0<CR>'<br>ModemManager[1133]: <debug> [1574094017.420240] (ttyAMA0): <-- '<CR><LF>OK<CR><LF>'<br>ModemManager[1133]: <debug> [1574094017.420584] (ttyAMA0) device open count is 4 (close)<br>ModemManager[1133]: <debug> [1574094017.420786] (ttyAMA0): --> 'AT+COPS?<CR>'<br>ModemManager[1133]: <debug> [1574094017.435034] (ttyAMA0): <-- '<CR><LF>+COPS:'<br>ModemManager[1133]: <debug> [1574094017.435707] (ttyAMA0): <-- ' 0,0,"mo'<br>ModemManager[1133]: <debug> [1574094017.436395] (ttyAMA0): <-- 'vistar",'<br>ModemManager[1133]: <debug> [1574094017.437102] (ttyAMA0): <-- '2<CR><LF><CR><LF>OK<CR>'<br>ModemManager[1133]: <debug> [1574094017.437484] (ttyAMA0): <-- '<LF>'<br>ModemManager[1133]: <debug> [1574094017.438034] loaded Operator Name: movistar<br>ModemManager[1133]: <info> [1574094017.438332] Modem /org/freedesktop/ModemManager1/Modem/0: 3GPP Registration state changed (registering -> home)<br>ModemManager[1133]: <debug> [1574094017.438692] Will start keeping track of state for subsystem '3gpp'<br>ModemManager[1133]: <debug> [1574094017.438854] (ttyAMA0) device open count is 3 (close)<br>ModemManager[1133]: <debug> [1574094017.439624] (ttyAMA0): --> 'AT+CIND?<CR>'<br>ModemManager[1133]: <debug> [1574094017.455505] (ttyAMA0): <-- '<CR><LF>+CIND:'<br>ModemManager[1133]: <debug> [1574094017.456197] (ttyAMA0): <-- ' 4,4,1,0'<br>ModemManager[1133]: <debug> [1574094017.456876] (ttyAMA0): <-- ',0,1,1,0'<br>ModemManager[1133]: <debug> [1574094017.457569] (ttyAMA0): <-- '<CR><LF><CR><LF>OK<CR><LF>'<br>ModemManager[1133]: <debug> [1574094017.458379] Modem /org/freedesktop/ModemManager1/Modem/0: signal quality updated (80)<br>ModemManager[1133]: <debug> [1574094017.458750] (ttyAMA0) device open count is 2 (close)<br>ModemManager[1133]: <debug> [1574094017.459450] Polling to refresh access technologies is unsupported<br>ModemManager[1133]: <debug> [1574094017.459576] Periodic signal quality checks scheduled in 30s<br>ModemManager[1133]: <debug> [1574094017.459730] (ttyAMA0): --> 'AT+CGDCONT?<CR>'<br>ModemManager[1133]: <debug> [1574094017.477723] (ttyAMA0): <-- '<CR><LF>+CGDCO'<br>ModemManager[1133]: <debug> [1574094017.478841] (ttyAMA0): <-- 'NT: 1,"I'<br>ModemManager[1133]: <debug> [1574094017.479712] (ttyAMA0): <-- 'P","inte'<br>ModemManager[1133]: <debug> [1574094017.480486] (ttyAMA0): <-- '<a href="http://rnet.movistar.co">rnet.movistar.co</a>'<br>ModemManager[1133]: <debug> [1574094017.481402] (ttyAMA0): <-- '<a href="http://m.co">m.co</a>","0'<br>ModemManager[1133]: <debug> [1574094017.482153] (ttyAMA0): <-- '.0.0.0",'<br>ModemManager[1133]: <debug> [1574094017.482855] (ttyAMA0): <-- '0,0<CR><LF>+CG'<br>ModemManager[1133]: <debug> [1574094017.483648] (ttyAMA0): <-- 'DCONT: 2'<br>ModemManager[1133]: <debug> [1574094017.484484] (ttyAMA0): <-- ',"IP","w'<br>ModemManager[1133]: <debug> [1574094017.485299] (ttyAMA0): <-- 'eb.colombiamovil'<br>ModemManager[1133]: <debug> [1574094017.486231] (ttyAMA0): <-- '.<a href="http://com.co">com.co</a>"'<br>ModemManager[1133]: <debug> [1574094017.487040] (ttyAMA0): <-- ',"0.0.0.'<br>ModemManager[1133]: <debug> [1574094017.487803] (ttyAMA0): <-- '0",0,0<CR><LF>'<br>ModemManager[1133]: <debug> [1574094017.488707] (ttyAMA0): <-- '+CGDCONT'<br>ModemManager[1133]: <debug> [1574094017.489554] (ttyAMA0): <-- ': 3,"IP","intern'<br>ModemManager[1133]: <debug> [1574094017.490384] (ttyAMA0): <-- 'et.movis'<br>ModemManager[1133]: <debug> [1574094017.491192] (ttyAMA0): <-- '<a href="http://tar.com">tar.com</a>.'<br>ModemManager[1133]: <debug> [1574094017.492093] (ttyAMA0): <-- 'co","0.0'<br>ModemManager[1133]: <debug> [1574094017.492957] (ttyAMA0): <-- '.0.0",0,0<CR><LF>+CGDC'<br>ModemManager[1133]: <debug> [1574094017.493782] (ttyAMA0): <-- 'ONT: 4,"'<br>ModemManager[1133]: <debug> [1574094017.494623] (ttyAMA0): <-- 'IP","mov'<br>ModemManager[1133]: <debug> [1574094017.495486] (ttyAMA0): <-- '<a href="http://iletb.ne">iletb.ne</a>'<br>ModemManager[1133]: <debug> [1574094017.496346] (ttyAMA0): <-- '<a href="http://t.co">t.co</a>","0'<br>ModemManager[1133]: <debug> [1574094017.497221] (ttyAMA0): <-- '.0.0.0",0,0<CR><LF><CR><LF>O'<br>ModemManager[1133]: <debug> [1574094017.498106] (ttyAMA0): <-- 'K<CR><LF>'<br>ModemManager[1133]: <debug> [1574094017.499204] Found '4' PDP contexts<br>ModemManager[1133]: <debug> [1574094017.499335] PDP context [cid=1] [type='ipv4'] [apn='<a href="http://internet.movistar.com.co">internet.movistar.com.co</a>']<br>ModemManager[1133]: <debug> [1574094017.499409] PDP context [cid=2] [type='ipv4'] [apn='<a href="http://web.colombiamovil.com.co">web.colombiamovil.com.co</a>']<br>ModemManager[1133]: <debug> [1574094017.499481] PDP context [cid=3] [type='ipv4'] [apn='<a href="http://internet.movistar.com.co">internet.movistar.com.co</a>']<br>ModemManager[1133]: <debug> [1574094017.499912] PDP context [cid=4] [type='ipv4'] [apn='<a href="http://moviletb.net.co">moviletb.net.co</a>']<br>ModemManager[1133]: <debug> [1574094017.500030] Found PDP context with CID 1 and PDP type ipv4 for APN '<a href="http://internet.movistar.com.co">internet.movistar.com.co</a>'<br>ModemManager[1133]: <debug> [1574094017.500192] (ttyAMA0) device open count is 3 (open)<br>ModemManager[1133]: <debug> [1574094017.500614] Connection through a plain serial AT port (ttyAMA0)<br>ModemManager[1133]: <debug> [1574094017.500772] (ttyAMA0) device open count is 4 (open)<br>ModemManager[1133]: <debug> [1574094017.501322] (ttyAMA0) device open count is 3 (close)<br>ModemManager[1133]: <debug> [1574094017.501539] (ttyAMA0): --> 'ATD*99***1#<CR>'<br>ModemManager[1133]: <debug> [1574094017.520418] (ttyAMA0): <-- '<CR><LF>CONNEC'<br>ModemManager[1133]: <debug> [1574094017.521287] (ttyAMA0): <-- 'T 115200'<br>ModemManager[1133]: <debug> [1574094017.522064] (ttyAMA0): <-- '<CR><LF>'<br>ModemManager[1133]: <debug> [1574094017.522990] (ttyAMA0): port now connected<br>ModemManager[1133]: <debug> [1574094017.523252] Connected bearer '/org/freedesktop/ModemManager1/Bearer/0'<br>ModemManager[1133]: <info> [1574094017.524890] Modem /org/freedesktop/ModemManager1/Modem/0: state changed (connecting -> connected)<br>ModemManager[1133]: <info> [1574094017.526928] Simple connect state (8/8): All done<br>ModemManager[1133]: <debug> [1574094017.528284] (ttyAMA0) device open count is 2 (close)<br>ModemManager[1133]: <debug> [1574094022.884121] Couldn't load network timezone: No AT port available to run command<br>ModemManager[1133]: <warn> [1574094022.884301] Couldn't load network timezone from the current network<br>ModemManager[1133]: <debug> [1574094047.903513] loading signal quality...<br>ModemManager[1133]: <debug> [1574094047.904192] Couldn't refresh signal quality: 'No AT port available to run command'<br>ModemManager[1133]: <debug> [1574094047.904316] Periodic signal quality checks scheduled in 30s<br>ModemManager[1133]: <debug> [1574094047.905267] Connection monitoring is unsupported by the device<br>ModemManager[1133]: <debug> [1574094077.908613] Signal quality value not updated in 60s, marking as not being recent<br>ModemManager[1133]: <debug> [1574094077.909225] loading signal quality...<br>ModemManager[1133]: <debug> [1574094077.912293] Couldn't refresh signal quality: 'No AT port available to run command'<br>ModemManager[1133]: <debug> [1574094077.913112] Periodic signal quality checks scheduled in 30s<br>ModemManager[1133]: <debug> [1574094107.909341] loading signal quality...<br>ModemManager[1133]: <debug> [1574094107.910887] Couldn't refresh signal quality: 'No AT port available to run command'<br>ModemManager[1133]: <debug> [1574094107.911877] Periodic signal quality checks scheduled in 30s<br>ModemManager[1133]: <debug> [1574094137.909770] loading signal quality...<br>ModemManager[1133]: <debug> [1574094137.910968] Couldn't refresh signal quality: 'No AT port available to run command'<br>ModemManager[1133]: <debug> [1574094137.911119] Periodic signal quality checks scheduled in 30s<br>ModemManager[1133]: <debug> [1574094167.909603] loading signal quality...<br>ModemManager[1133]: <debug> [1574094167.910793] Couldn't refresh signal quality: 'No AT port available to run command'<br>ModemManager[1133]: <debug> [1574094167.910940] Periodic signal quality checks scheduled in 30s<br>ModemManager[1133]: <debug> [1574094197.909420] loading signal quality...<br>ModemManager[1133]: <debug> [1574094197.910612] Couldn't refresh signal quality: 'No AT port available to run command'<br>ModemManager[1133]: <debug> [1574094197.910761] Periodic signal quality checks scheduled in 30s<br>ModemManager[1133]: <debug> [1574094227.908847] loading signal quality...<br>ModemManager[1133]: <debug> [1574094227.910030] Couldn't refresh signal quality: 'No AT port available to run command'<br>ModemManager[1133]: <debug> [1574094227.910179] Periodic signal quality checks scheduled in 30s <br></div><div><br></div><div><div>PS: same issue has been reported here (unsolved)</div><div><a href="https://serverfault.com/questions/990028/networkmanager-gsm-connection-on-simcom-sim5320a-via-serial-port-is-failing">https://serverfault.com/questions/990028/networkmanager-gsm-connection-on-simcom-sim5320a-via-serial-port-is-failing</a></div></div><div><br></div><br></div>