sierra wireless compass 597 aircard (Was: Documentation)

Fredrik Lindberg fli at
Wed May 7 19:17:40 UTC 2008

Steve Clark wrote:
> Fredrik Lindberg wrote:
>> Marcin Cieslak wrote:
>>> It maybe a good idea to add 0xFFF to the usbdevs.
>>> Does the "umass" driver  attach to the 0xFFF device? I would 
>>> recommend adding this as a quirk to umass.c then.
>>> There are patches attached (ubsa.c_patch, umass_c.patch, 
>>> usbdevs.patch) I am using to kill the "zeroconf" CD on the UMTS. They 
>>> do not always work - i.e. umass_attach does not wait until the device 
>>> is really detached. But setting USB_DEBUG helps :-)
>> Since your patches deals with Option cards I'll just let you know that
>> all(?) Option based devices can be switched perfectly safe from
>> user land, without patching ubsa, using camcontrol.
>> The command to switch Option devices is a SCSI REZERO command.
>> This should be enough to switch the device, given that pass0
>> is the modem (use camcontrol devlist)
>> camcontrol cmd pass0 -c “01 00 00 00 00 00″ -i 1 i1
>> camcontrol might give you an error but the device will be switched.
>> Note that this is ONLY for Option based devices, I don't know about
>> the Sierra ones but the linux usb_modeswitch tool might be a good start.
>> Fredrik
> Hi Fredrik,
> This does not seem to work for me with the sierra usb device.

No, as I said it's for devices from Option ( My
comment was actually more directed to Marcin since his patches
dealt with Option devices.

Sorry for the semi thread hijacking.

I personally think it's a bad idea to put the code for "switching"
these kind of devices inside the kernel. Drivers will become cluttered
with switching code for different kinds of devices and it will
prevent anybody from actually reading was on the "Zero-CD" device.
Besides, I'm quite sure all devices can be switched from user land,
one way or another.

In my opinion, what's really needed is some sort of generic dynamic
black listing which can prevent drivers from attaching to devices.
For usb devices one can then simply send the magic switch sequences
through a ugen device. The usb_modeswitch tool does exactly that.


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