I just rebuild kernel ,and modulize the ohci-hcd.ko

the command I used to change storage mode to modem mode look like :

usb_modeswitch -v 0x19d2 -p 0xfff6 -m 0a -M 5553424312345678000000000000061b000000030000000000000000000000
usb_modeswitch -v 0x19d2 -p 0xfff6 -m 0a -M ...

Josh wrote:Did you try any ZTE configurations from the config file?

yes , I try every ZTE configurations from the config file, but not work

It seem ZTE AC8710 with storage, and it vendor id = 0x19d2, product id = 0xfff6, but I can't switch storage mode to modem mode

insmod ohci-hcd.ko
rmmod usb-storage.ko
insmod usbserial.ko vendor=0x19d2 product=0xfff6

only can get ttyUSB0 and can't get ATCOMMAND's response
I need a help to do mode ...

But I ust ttyUSB0 to connect
ttyUSB1 can't usb AT COMMAND
ttyUSB2, ttyUSB3 can get status when ttyUSB0 is connecting.

For dialing I use pppd, too.

What device you use to connect ? (ttyUSB0 ~ 3)
What tools yous use to dial ? (pppd, wvdial, kppp)

Thanks both Josh and mixmaxtw !!!
In my system, there is nothing in /sys/bus/usb/devices/1-2/, so I try to find out the folder and file.
When I can echo "suspend" to /sys/bus/usb/devices/1-2/power/level , the magic thing happened !!
The way "echo suspend > /sys/bus/usb/devices/1-2/power/level ...

I use MU-Q101 with linux (kernel: 2.6.22.10)

usb 2-2: new full speed USB device using ohci_hcd and address 17
usb 2-2: device descriptor read/64, error -62
usb 2-2: device descriptor read/64, error -62
usb 2-2: new full speed USB device using ohci_hcd and address 18
usb 2-2: device descriptor read ...