Connection to a 3G USB Module using USB-Serial

Connection to a 3G USB Module using USB-Serial

[Fabio Fumi]

I'm struggling with this issue since a while and as the author of the
USB-Serial module I thought experts here might provide some help... As
it's a USB-serail issue, I've posted on both USB and Serial lists.
thanks in advance!

The problem is about connecting with a 3G USB modem, a ZTE MF-210
mini-pci board; plugged as a daughter board inside an Android tablet.
I have posted already on a couple forums, but got no useful feedback
yet.

As soon as I power up the module I get the expected /dev/ttyUSB0-3 and
that's fine, so far:

<6>usb 1-1.1: new high speed USB device using emxx-ehci-driver and address 3
<6>option 1-1.1:1.0: GSM modem (1-port) converter detected
<6>usb 1-1.1: GSM modem (1-port) converter now attached to ttyUSB0
<6>option 1-1.1:1.1: GSM modem (1-port) converter detected
<6>usb 1-1.1: GSM modem (1-port) converter now attached to ttyUSB1
<6>option 1-1.1:1.2: GSM modem (1-port) converter detected
<6>usb 1-1.1: GSM modem (1-port) converter now attached to ttyUSB2
<6>option 1-1.1:1.3: GSM modem (1-port) converter detected
<6>usb 1-1.1: GSM modem (1-port) converter now attached to ttyUSB3

Issue is when I try to communicate with any of these ports. I can
connect using picocom to all but can't receive any feedback from AT
commands sent over to them. I made some partial progress only after
using the "-i" option (i.e. "no port init"), but below you can find
what I get if I simply type A + T + Z + <enter>, for example.

As you can see, characters and commands are repeated several times.
That's what I can't understand.

Without the -i option, I don't even get any feedback from the modem
and the same happens using other connection programs, e.g. busybox
microcom. I'm using picocom as it's very small and I succesfully used
it already in a similar case, though on a different Android platform
and kernel.

This Kernel is built including standard usb-serial options below:

CONFIG_USB_SERIAL=y
CONFIG_USB_SERIAL_WWAN=y
CONFIG_USB_SERIAL_OPTION=y

Is the kernel missing anything, or requiring some special ZTE-specific
customizations in your opinion?

What are the best connection options I could try?

 thanks

Re: Connection to a 3G USB Module using USB-Serial

[Greg KH]

On Thu, May 30, 2013 at 02:54:40PM +0200, Fabio Fumi wrote:
> I'm struggling with this issue since a while and as the author of the
> USB-Serial module I thought experts here might provide some help... As
> it's a USB-serail issue, I've posted on both USB and Serial lists.
> thanks in advance!
> 
> The problem is about connecting with a 3G USB modem, a ZTE MF-210
> mini-pci board; plugged as a daughter board inside an Android tablet.
> I have posted already on a couple forums, but got no useful feedback
> yet.
> 
> As soon as I power up the module I get the expected /dev/ttyUSB0-3 and
> that's fine, so far:
> 
> <6>usb 1-1.1: new high speed USB device using emxx-ehci-driver and address 3
> <6>option 1-1.1:1.0: GSM modem (1-port) converter detected
> <6>usb 1-1.1: GSM modem (1-port) converter now attached to ttyUSB0
> <6>option 1-1.1:1.1: GSM modem (1-port) converter detected
> <6>usb 1-1.1: GSM modem (1-port) converter now attached to ttyUSB1
> <6>option 1-1.1:1.2: GSM modem (1-port) converter detected
> <6>usb 1-1.1: GSM modem (1-port) converter now attached to ttyUSB2
> <6>option 1-1.1:1.3: GSM modem (1-port) converter detected
> <6>usb 1-1.1: GSM modem (1-port) converter now attached to ttyUSB3
> 
> Issue is when I try to communicate with any of these ports. I can
> connect using picocom to all but can't receive any feedback from AT
> commands sent over to them. I made some partial progress only after
> using the "-i" option (i.e. "no port init"), but below you can find
> what I get if I simply type A + T + Z + <enter>, for example.
> 
> As you can see, characters and commands are repeated several times.
> That's what I can't understand.
> 
> Without the -i option, I don't even get any feedback from the modem
> and the same happens using other connection programs, e.g. busybox
> microcom. I'm using picocom as it's very small and I succesfully used
> it already in a similar case, though on a different Android platform
> and kernel.
> 
> This Kernel is built including standard usb-serial options below:
> 
> CONFIG_USB_SERIAL=y
> CONFIG_USB_SERIAL_WWAN=y
> CONFIG_USB_SERIAL_OPTION=y

What kernel version are you using?

> Is the kernel missing anything, or requiring some special ZTE-specific
> customizations in your opinion?

There is a new zte-specific driver in the 3.9 kernel release that should
work for your device.  We just got some patches merged that moved the
device id from the option driver to the zte driver, which should resolve
issues like the one you are seeing here (i.e. the wrong driver
controlling the device.)  Can you test the 3.10-rc5 kernel that comes
out in a few days, or the next 3.9-stable release 3.9.6 should have the
proper patches)?

thanks,

greg k-h
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: Connection to a 3G USB Module using USB-Serial

[Fabio Fumi]

Thanks Greg for taking som etime to answer.

My kernel is an old 2.6.35.7 and migrating it entirely to 3+ one is a
real mess (given the number of platfomr customization it includes). So
probably the best is to try back-porting the ZTE usb-serial driver...
I guess. Is it "drivers/usb/serial/zte_ev.c" what you're referring to?
My device is a ZTE MF-210... does the same driver really apply for
this device too?

Does the same driver rely on some kernel 3.x-only features?
I can always give it a *blind* try, of course... but better knowing in
advance, if it won't work.

On Sat, Jun 8, 2013 at 8:22 PM, Greg KH <greg@kroah.com> wrote:
> On Thu, May 30, 2013 at 02:54:40PM +0200, Fabio Fumi wrote:
>> I'm struggling with this issue since a while and as the author of the
>> USB-Serial module I thought experts here might provide some help... As
>> it's a USB-serail issue, I've posted on both USB and Serial lists.
>> thanks in advance!
>>
>> The problem is about connecting with a 3G USB modem, a ZTE MF-210
>> mini-pci board; plugged as a daughter board inside an Android tablet.
>> I have posted already on a couple forums, but got no useful feedback
>> yet.
>>
>> As soon as I power up the module I get the expected /dev/ttyUSB0-3 and
>> that's fine, so far:
>>
>> <6>usb 1-1.1: new high speed USB device using emxx-ehci-driver and address 3
>> <6>option 1-1.1:1.0: GSM modem (1-port) converter detected
>> <6>usb 1-1.1: GSM modem (1-port) converter now attached to ttyUSB0
>> <6>option 1-1.1:1.1: GSM modem (1-port) converter detected
>> <6>usb 1-1.1: GSM modem (1-port) converter now attached to ttyUSB1
>> <6>option 1-1.1:1.2: GSM modem (1-port) converter detected
>> <6>usb 1-1.1: GSM modem (1-port) converter now attached to ttyUSB2
>> <6>option 1-1.1:1.3: GSM modem (1-port) converter detected
>> <6>usb 1-1.1: GSM modem (1-port) converter now attached to ttyUSB3
>>
>> Issue is when I try to communicate with any of these ports. I can
>> connect using picocom to all but can't receive any feedback from AT
>> commands sent over to them. I made some partial progress only after
>> using the "-i" option (i.e. "no port init"), but below you can find
>> what I get if I simply type A + T + Z + <enter>, for example.
>>
>> As you can see, characters and commands are repeated several times.
>> That's what I can't understand.
>>
>> Without the -i option, I don't even get any feedback from the modem
>> and the same happens using other connection programs, e.g. busybox
>> microcom. I'm using picocom as it's very small and I succesfully used
>> it already in a similar case, though on a different Android platform
>> and kernel.
>>
>> This Kernel is built including standard usb-serial options below:
>>
>> CONFIG_USB_SERIAL=y
>> CONFIG_USB_SERIAL_WWAN=y
>> CONFIG_USB_SERIAL_OPTION=y
>
> What kernel version are you using?
>
>> Is the kernel missing anything, or requiring some special ZTE-specific
>> customizations in your opinion?
>
> There is a new zte-specific driver in the 3.9 kernel release that should
> work for your device.  We just got some patches merged that moved the
> device id from the option driver to the zte driver, which should resolve
> issues like the one you are seeing here (i.e. the wrong driver
> controlling the device.)  Can you test the 3.10-rc5 kernel that comes
> out in a few days, or the next 3.9-stable release 3.9.6 should have the
> proper patches)?
>
> thanks,
>
> greg k-h

Re: Connection to a 3G USB Module using USB-Serial

[Greg KH]

On Mon, Jun 10, 2013 at 03:58:38PM +0200, Fabio Fumi wrote:
> Thanks Greg for taking som etime to answer.
> 
> My kernel is an old 2.6.35.7 and migrating it entirely to 3+ one is a
> real mess (given the number of platfomr customization it includes).

Ick, really old obsolete kernels like that one are not good for trying
to run new hardware with.  I suggest contacting the company that is
forcing you to stick with that version, and getting support from them to
do the needed backporting of this driver.

> So probably the best is to try back-porting the ZTE usb-serial
> driver...  I guess. Is it "drivers/usb/serial/zte_ev.c" what you're
> referring to?  My device is a ZTE MF-210... does the same driver
> really apply for this device too?

I think it does, what is the device/vendor id of it?

> Does the same driver rely on some kernel 3.x-only features?

Yes, all drivers are tied tightly to the specific kernel version they
are released with.

> I can always give it a *blind* try, of course... but better knowing in
> advance, if it won't work.

You can try to backport it, it shouldn't be that hard, but your really
going to be on your own here, sorry.

best of luck,

greg k-h