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
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
