Hello!
I have an MC8790 installed in an ARM system running Linux 3.0.4 using the sierra driver as a module.
The modem works as expected - I can query it for information using AT codes and set up a working PPP connection with my provider.
The problem:
When there is no reception (such as when the external antenna is removed or when a SIM is inserted which is out of range of its home station) the modem periodically (3-4 times per minute) disconnects itself from the USB and then reconnects after a few seconds.
This in itself is not a fatal problem, but after some random number of disconnect/connect cycles the modem no longer fully reconnects. Where there are usually seven serial lines /dev/ttyUSB[0-6] there is now only one, /dev/ttyUSB0, and a “ùsb storage device” /dev/sda.
The modem stays in this state (though still reconnecting periodically) until it is fully power cycled (i.e. the system fully powered off or the modem physically removed from the system and then reinserted). Simply rebooting the host system does not help if power is not fully removed.
Here is some information I’ve dumped from the modem using a chatscript when a SIM out of range is inserted:
AT
OK
AT+CFUN=1
OK
AT&V
&C: 1; &D: 2; &E: 1; &F: 0; &S: 0; &W: 0; E: 1; L: 0; M: 0; Q: 0; V: 1;
X: 1; Z: 0; \Q: 3; \S: 0; \V: 0; S0: 0; S2: 43; S3: 13; S4: 10; S5: 8;
S6: 2; S7: 50; S8: 2; S9: 6; S10: 14; S11: 95; S30: 0; S103: 1; S104: 1;
+FCLASS: 0; +ICF: 3,3; +IFC: 2,2; +IPR: 115200; +DR: 0; +DS: 0,0,2048,6;
+WS46: 12; +CBST: 0,0,1;
+CRLP: (61,61,48,6,0),(61,61,48,6,1),(240,240,52,6,2);
+CV120: 1,1,1,0,0,0; +CHSN: 0,0,0,0; +CSSN: 0,0; +CREG: 0; +CGREG: 0;
+CFUN:; +CSCS: "IRA"; +CSTA: 129; +CR: 0; +CRC: 0; +CMEE: 2; +CGDCONT: (1,"IP","internet.telenor.se","0.0.0.0",0,0)
; +CGDSCONT: ; +CGTFT: ; +CGEQREQ: ; +CGEQMIN: ; +CGQREQ: ; +CGQMIN: ;
+CGEREP: 0,0; +CGDATA: "PPP"; +CGCLASS: "A"; +CGSMS: 0; +CSMS: 0;
+CMGF: 0; +CSAS: 0; +CRES: 0; +CSCA: "",; +CSMP: ,,0,0; +CSDH: 0;
+CSCB: 0,"",""; +FDD: 0; +FAR: 0; +FCL: 0; +FIT: 0,0; +ES: ,,;
+ESA: 0,,,,0,0,255,; +CMOD: 0; +CVHU: 0; +CPIN: ^?^?^?^?^?^?^?^?,^?^?^?^?^?^?^?^?;
+CMEC: 0,0,0; +CKPD: 1,1; +CIND: 0,0,0,0,0,0,0,0; +CMER: 0,0,0,0,0;
+CGATT: 0; +CGACT: 0; +CPBS: "SM"; +CPMS: "SM","SM","SM";
+CNMI: 0,0,0,0,0; +CMMS: 0; +FTS: 0; +FRS: 0; +FTH: 3; +FRH: 3; +FTM: 96;
+FRM: 96; +CCUG: 0,0,0; +COPS: 0,0,""; +CUSD: 0; +CAOC: 1; +CCWA: 0;
+CCLK: ""; +CPOL: 0,2,"",0,0,0; +CPLS: 0; +CTZR: 0; +CTZU: 0; +CLIP: 0;
+COLP: 0; +CDIP: 0; +CLIR: 0; +CMUX: 0,0,5,31,10,3,30,10,2;
!CMUX: 0,0,5,31,10,3,30,10,2
OK
AT+CPOL?
+CPOL: 1,2,"23801"
+CPOL: 2,2,"24491"
+CPOL: 3,2,"24202"
OK
AT+COPS=3,0
OK
AT+COPS?
+COPS: 0
OK
AT+COPS=3,2
OK
AT+COPS?
+COPS: 0
OK
AT+CGREG?
+CGREG: 0,0
OK
AT^SYSCONFIG?
^SYSCONFIG: 2,2,1,2
OK
AT^SYSINFO
^SYSINFO: 0,0,0,0,1
OK
AT!GSTATUS?
!GSTATUS:
Current Time: 208^I^ITemperature: 44
Bootup Time: 202^I^IMode: ONLINE
System mode: GSM ^IPS state: Not attached
WCDMA band: IMT2000 ^IGSM band: Unknown
WCDMA channel: 10787^I^IGSM channel: 65535
GMM (PS) state:DEREGISTERED ^IPLMN SEARCH
MM (CS) state: IDLE ^IPLMN SEARCH
WCDMA L1 State:L1M_BCH ^IRRC State: DISCONNECTED
RX level (dBm):-90
OK
AT!GSMINFO?
!GSMINFO:
Serving Cell:
Not Available
OK
AT!PCVOLT?
Volt state: Normal
Power supply voltage: 3304 mV (163 cnt)
OK
AT!GVER?
!GVER: K2_0_7_35AP C:/WS/FW/K2_0_7_35AP/MSM6290/SRC 2010/03/04 17:37:08
OKHere is my dmesg showing the moment when the proper state is lost and the modem goes into the problem state:
usb 1-3: new high speed USB device number 7 using ehci_hcd
usb 1-3: New USB device found, idVendor=1199, idProduct=683c
usb 1-3: New USB device strings: Mfr=3, Product=2, SerialNumber=0
usb 1-3: Product: MC8790
usb 1-3: Manufacturer: Sierra Wireless, Incorporated
sierra 1-3:1.0: Sierra USB modem converter detected
usb 1-3: Sierra USB modem converter now attached to ttyUSB0
sierra 1-3:1.1: Sierra USB modem converter detected
usb 1-3: Sierra USB modem converter now attached to ttyUSB1
sierra 1-3:1.2: Sierra USB modem converter detected
usb 1-3: Sierra USB modem converter now attached to ttyUSB2
sierra 1-3:1.3: Sierra USB modem converter detected
usb 1-3: Sierra USB modem converter now attached to ttyUSB3
sierra 1-3:1.4: Sierra USB modem converter detected
usb 1-3: Sierra USB modem converter now attached to ttyUSB4
sierra 1-3:1.5: Sierra USB modem converter detected
usb 1-3: Sierra USB modem converter now attached to ttyUSB5
sierra 1-3:1.6: Sierra USB modem converter detected
usb 1-3: Sierra USB modem converter now attached to ttyUSB6
usb 1-3: USB disconnect, device number 7
sierra ttyUSB0: Sierra USB modem converter now disconnected from ttyUSB0
sierra 1-3:1.0: device disconnected
sierra ttyUSB1: Sierra USB modem converter now disconnected from ttyUSB1
sierra 1-3:1.1: device disconnected
sierra ttyUSB2: Sierra USB modem converter now disconnected from ttyUSB2
sierra 1-3:1.2: device disconnected
sierra ttyUSB3: Sierra USB modem converter now disconnected from ttyUSB3
sierra 1-3:1.3: device disconnected
sierra ttyUSB4: Sierra USB modem converter now disconnected from ttyUSB4
sierra 1-3:1.4: device disconnected
sierra ttyUSB5: Sierra USB modem converter now disconnected from ttyUSB5
sierra 1-3:1.5: device disconnected
sierra ttyUSB6: Sierra USB modem converter now disconnected from ttyUSB6
sierra 1-3:1.6: device disconnected
usb 1-3: new high speed USB device number 8 using ehci_hcd
usb 1-3: New USB device found, idVendor=1199, idProduct=683c
usb 1-3: New USB device strings: Mfr=3, Product=2, SerialNumber=0
usb 1-3: Product: MC8790
usb 1-3: Manufacturer: Sierra Wireless, Incorporated
sierra 1-3:1.0: Sierra USB modem converter detected
usb 1-3: Sierra USB modem converter now attached to ttyUSB0Summary
- What causes the modem to reconnect when there is no base station?
- What is this mode where the modem only provides a single serial interface? Is there a way to get out of it through software means?
Thank you kindly for your responses!