Re: Huawei E372 12d1:1506 reports itself as E398

[Bjørn Mork <bjorn@xxxxxxx>]

Bjørn Mork <bjorn@xxxxxxx> writes:

> Ideally the modem firmware should have handled this gracefully, but I
> don't expect that to really happen... 

FWIW, Sierra Wireless have obviously implemented mutual exclusion
between PPP and ethernet emulation in their firmware.  ttyUSB2 is a
serial port supporting ppp and cdc-wdm0 is a QMI device on the same USB
modem: 

 bjorn@nemi:~$  ls -ld /sys/bus/usb/devices/2-4:*/{net/*,usb/*,tty*}
 drwxr-xr-x 4 root root 0 May 22 08:48 /sys/bus/usb/devices/2-4:1.0/ttyUSB0
 drwxr-xr-x 4 root root 0 May 22 08:48 /sys/bus/usb/devices/2-4:1.2/ttyUSB1
 drwxr-xr-x 4 root root 0 May 22 08:48 /sys/bus/usb/devices/2-4:1.3/ttyUSB2
 drwxr-xr-x 5 root root 0 May 22 08:48 /sys/bus/usb/devices/2-4:1.8/net/wwan0
 drwxr-xr-x 3 root root 0 May 22 08:48 /sys/bus/usb/devices/2-4:1.8/usb/cdc-wdm0


Attempting PPP while connected via QMI/wwan:

 nemi:/home/bjorn# pppd noauth debug nodetach connect "chat -V '' ATDT*99# ABORT 'NO CARRIER' CONNECT" /dev/ttyUSB2
 ATDT*99#
 NO CARRIERScript chat -V '' ATDT*99# ABORT 'NO CARRIER' CONNECT finished (pid 26609), status = 0x4
 Connect script failed

Disconnecting QMI:

 bjorn@nemi:/usr/local/src/git/libqmi-glib$ PATH=cli:$PATH utils/qmi-network /dev/cdc-wdm0 stop
 Loading previous state...
     Previous CID: 1
     Previous PDH: 39639200
 Stopping network with 'qmicli -d /dev/cdc-wdm0 --wds-stop-network=39639200 --client-cid=1'...
 Network stopped successfully
 Clearing state...

PPP now works:

 nemi:/home/bjorn# pppd noauth debug nodetach connect "chat -V '' ATDT*99# ABORT 'NO CARRIER' CONNECT" /dev/ttyUSB2
 ATDT*99#
 CONNECTScript chat -V '' ATDT*99# ABORT 'NO CARRIER' CONNECT finished (pid 26628), status = 0x0
 Serial connection established.
 using channel 1
 Using interface ppp0
 Connect: ppp0 <--> /dev/ttyUSB2
 sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0xaf01574f> <pcomp> <accomp>]
 rcvd [LCP ConfReq id=0x0 <asyncmap 0x0> <auth chap MD5> <magic 0xd8fbaea5> <pcomp> <accomp>]
 No auth is possible
 sent [LCP ConfRej id=0x0 <auth chap MD5>]
 rcvd [LCP ConfAck id=0x1 <asyncmap 0x0> <magic 0xaf01574f> <pcomp> <accomp>]
 rcvd [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0xd8fbaea5> <pcomp> <accomp>]
 sent [LCP ConfAck id=0x1 <asyncmap 0x0> <magic 0xd8fbaea5> <pcomp> <accomp>]
 sent [LCP EchoReq id=0x0 magic=0xaf01574f]
 sent [CCP ConfReq id=0x1 <deflate 15> <deflate(old#) 15> <bsd v1 15>]
 sent [IPCP ConfReq id=0x1 <compress VJ 0f 01> <addr 0.0.0.0>]
 rcvd [LCP DiscReq id=0x2 magic=0xd8fbaea5]
 rcvd [LCP EchoRep id=0x0 magic=0xd8fbaea5 af 01 57 4f]
 rcvd [LCP ProtRej id=0x3 80 fd 01 01 00 0f 1a 04 78 00 18 04 78 00 15 03 2f]
 Protocol-Reject for 'Compression Control Protocol' (0x80fd) received
 rcvd [IPCP ConfReq id=0x0]
 sent [IPCP ConfNak id=0x0 <addr 0.0.0.0>]
 rcvd [IPCP ConfRej id=0x1 <compress VJ 0f 01>]
 sent [IPCP ConfReq id=0x2 <addr 0.0.0.0>]
 rcvd [IPCP ConfReq id=0x1]
 sent [IPCP ConfAck id=0x1]
 rcvd [IPCP ConfNak id=0x2 <addr 10.105.75.185>]
 sent [IPCP ConfReq id=0x3 <addr 10.105.75.185>]
 rcvd [IPCP ConfAck id=0x3 <addr 10.105.75.185>]
 Could not determine remote IP address: defaulting to 10.64.64.64
 local  IP address 10.105.75.185
 remote IP address 10.64.64.64
 Script /etc/ppp/ip-up started (pid 26637)
 Script /etc/ppp/ip-up finished (pid 26637), status = 0x0

Attempting to start a network connection via QMI while the PPP session
is up fails:

 bjorn@nemi:/usr/local/src/git/libqmi-glib$ PATH=cli:$PATH utils/qmi-network /dev/cdc-wdm0 start
 Starting network with 'qmicli -d /dev/cdc-wdm0 --wds-start-network  --client-no-release-cid'...
 error: couldn't start network: QMI protocol error (14): 'call-failed'
 call end reason: 1
 verbose call end reason: 204, 2
 Saving state... (CID: 2)
 error: network start failed, no packet data handle
 Clearing state...

Bring down the PPP session, and QMI works again:

 ^CTerminating on signal 2
 Connect time 5.1 minutes.
 Sent 0 bytes, received 0 bytes.
 Script /etc/ppp/ip-down started (pid 26709)
 sent [LCP TermReq id=0x2 "User request"]
 rcvd [LCP TermAck id=0x2]
 Connection terminated.
 Script /etc/ppp/ip-down finished (pid 26709), status = 0x0

 bjorn@nemi:/usr/local/src/git/libqmi-glib$ PATH=cli:$PATH utils/qmi-network /dev/cdc-wdm0 start
 Starting network with 'qmicli -d /dev/cdc-wdm0 --wds-start-network  --client-no-release-cid'...
 Saving state... (CID: 3)
 Saving state... (PDH: 39639200)
 Network started successfully


This is how things *should* work, but modem firmware quality is one of
the few remaining differences between the manufacturers...


Bjørn
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