hi,
with the attitude 12.09 and some extra packages my 3g stick works.
with the 14.07 however, i have no luck (yet)
i do not seem to get any dev/ttyUSBx device which i believe is the reason it does not work
any suggestion is appreciated.
i spent hours yet trying to get that device working....

(updated 3nov)

the firmware i use is barrier_breaker14.07-ar71xx-generic
the usb stick is some e1552/e1800 huawei clone
this is confirmed by the usbutils package but because they take alot of space so i had to remove them

root@OpenWrt:~# dmesg |grep usb  (after reboot)

[    4.080000] usbcore: registered new interface driver usbfs
[    4.090000] usbcore: registered new interface driver hub
[    4.090000] usbcore: registered new device driver usb
[   10.990000] usbcore: registered new interface driver cdc_acm
[   11.090000] usbcore: registered new interface driver usbserial
[   11.110000] usbcore: registered new interface driver usbserial_generic
[   11.110000] usbserial: USB Serial support registered for generic
[   11.480000] usbcore: registered new interface driver option
[   11.500000] usbserial: USB Serial support registered for GSM modem (1-port)
[   66.490000] usb 1-1: new full-speed USB device number 2 using ehci-platform

some more info:
root@OpenWrt:~# opkg list-installed | grep usb
kmod-ledtrig-usbdev - 3.10.49-1
kmod-usb-acm - 3.10.49-1
kmod-usb-core - 3.10.49-1
kmod-usb-ohci - 3.10.49-1
kmod-usb-serial - 3.10.49-1
kmod-usb-serial-option - 3.10.49-1
kmod-usb-serial-wwan - 3.10.49-1
kmod-usb2 - 3.10.49-1
libusb-1.0 - 1.0.9-1
libusb-compat - 0.1.4-1

root@OpenWrt:~# ls /sys/bus/usb-serial/drivers/generic
bind    module  new_id  uevent  unbind

root@OpenWrt:~# ls /proc/bus
pci

root@OpenWrt:~# ls /etc/modules.d
09-crypto-arc4          50-usb-ohci             ppp
20-ipv6                 ath9k                   pppoe
20-usb-core             ipt-conntrack           usb-acm
30-gpio-button-hotplug  ipt-core                usb-serial
40-usb2                 ipt-nat                 usb-serial-option
42-ip6tables            ipt-nathelper           usb-serial-wwan
50-ledtrig-usbdev       lib-crc-ccitt

root@OpenWrt:/dev# cat /sys/kernel/debug/usb/devices

T:  Bus=01 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#=  1 Spd=480  MxCh= 1
B:  Alloc=  0/800 us ( 0%), #Int=  0, #Iso=  0
D:  Ver= 2.00 Cls=09(hub  ) Sub=00 Prot=01 MxPS=64 #Cfgs=  1
P:  Vendor=1d6b ProdID=0002 Rev= 3.10
S:  Manufacturer=Linux 3.10.49 ehci_hcd
S:  Product=EHCI Host Controller
S:  SerialNumber=ehci-platform
C:* #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr=  0mA
I:* If#= 0 Alt= 0 #EPs= 1 Cls=09(hub  ) Sub=00 Prot=00 Driver=hub
E:  Ad=81(I) Atr=03(Int.) MxPS=   4 Ivl=256ms

T:  Bus=01 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#=  4 Spd=12   MxCh= 0
D:  Ver= 1.10 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs=  1
P:  Vendor=12d1 ProdID=1446 Rev= 0.00
S:  Manufacturer=Qualcomm, Incorporated
S:  Product=USB MMC Storage
S:  SerialNumber=ÿÿÿÿÿÿÿÿÿÿÿÿ
C:* #Ifs= 1 Cfg#= 1 Atr=a0 MxPwr=500mA
I:* If#= 0 Alt= 0 #EPs= 2 Cls=08(stor.) Sub=06 Prot=50 Driver=(none)
E:  Ad=85(I) Atr=02(Bulk) MxPS=  64 Ivl=0ms
E:  Ad=05(O) Atr=02(Bulk) MxPS=  64 Ivl=0ms

root@OpenWrt:/sys/bus/usb-serial/drivers# ls
generic  option1

(Last edited by sohoto on 3 Nov 2014, 18:48)

ok seems the modedswitch was needed after all
currently only needed extra packages:
luci-proto-3g  usb-modeswitch  kmod-usb-serial kmod-usb-serial-wwan kmod-usb-serial-option
still having issues as i seem the switch not always does a switch automatically...  also
still discs with "No response to 5 echo-requests" but i'll sort that out and update this if i can

update 5-11:
been reinstalling and testing and going on with r42625 and i strangely no longer have "no response to" issues...
however i got another issue coming up.
after a certain time (can be 1h....5 minutes,...) my wan connection drops with a strange message.
after that i have to reboot to get it back up.

the message does not make sense....
it does not seem to be a power ussue since i'm using the regular power usb cable and although
wifi is active its at low power output while nothing else is connected on that interface
(even without wifi i get this issue)
will look further...

with debug 4 logging:
...
procd: watchdog_timeout_cb(37): Ping
procd: watchdog_timeout_cb(37): Ping
[  274.330000] usb 1-1: USB disconnect, device number 2
[  274.330000] option1 ttyUSB0: option_instat_callback: error -143
[  274.340000] option1 ttyUSB0: usb_wwan_indat_callback: resubmit read urb failed. (-19)

(Last edited by sohoto on 5 Nov 2014, 20:27)

ok... i restored the original TP firmware just to be sure.
seems i also have those usb disconnects here.
now it is either the usb stick worth jack sh1t or the 3020.
the default power adaptor is 5V/1A which should be ok.
this is really pissing me off...

(Last edited by sohoto on 5 Nov 2014, 23:26)

Install usbmodeswitch-data package. It contain real command for modem swtching

with 12.09 yes but this is already included by default in v14

""as of r36812, usb-modeswitch package had been under major overhaul from ordinary draisberghof usb_modeswitch found in many linux distributions. usb-modeswitch-data is included in the package, with the new json format. ""

my current issue seems to be an usb issue (usb stick disconnects) ,
i will test with a powered hub if i can get one soon to rule that out or run it a computer USB port directly

update:
tried with a powered hub...works even less....
45 1st day 00:20:17 3G/4G INFO sw3GMobileCmdReq 449 mobileFormatCmd error
44 1st day 00:20:15 3G/4G NOTICE Reset the 3G modem, please wait.
43 1st day 00:19:49 3G/4G INFO Run 3G dial cmd: pppd 3g 1 /dev/ttyUSB0 115200 connect "chat -s -v -f /etc/ppp/c
42 1st day 00:19:49 3G/4G NOTICE 3G/4G start connecting...
41 1st day 00:19:36 3G/4G INFO sw3GMobileCmdReq 449 mobileFormatCmd error
40 1st day 00:19:36 3G/4G WARNING 3G Modem connecting error, please check the dial number and APN.
39 1st day 00:19:09 3G/4G INFO Run 3G dial cmd: pppd 3g 1 /dev/ttyUSB0 115200 connect

(Last edited by sohoto on 6 Nov 2014, 21:48)