Sierra MC7354

[Bjørn Mork]

szlin <lin.sunze at gmail.com> writes:

> 2014-03-10 23:19 GMT+08:00 Bjørn Mork <bjorn at mork.no>:
>> szlin <lin.sunze at gmail.com> writes:
>>
>>> Hi,
>>>
>>> Module name:          Sierra MC7354
>>> Vendor/Product ID:  0x1199/ 0x68c0
>>
>> huh? Is that device supported by qmi_wwan?  Care to send a patch?
>>
>
> Sure, I'll send workable patch after resolving this issue.

Great.  Thanks.

Is this an "embedded version", or is it a generic module intended for
laptops?  Does it come with just a single QMI configuration enabled?
Is there more than one QMI interface there?


>>> LIBQMI version:      1.8
>>> Linux version:          3.12
>>>
>>> I got the following error message *in sometimes*, after seeing that ,
>>> system will be crashed.
>>>
>>> #qmi-network /dev/cdc-wdm0 start
>>> Loading profile...
>>>     APN: Internet
>>> Starting network with 'qmicli -d /dev/cdc-wdm0
>>> --wds-start-network=Internet  --client-no-release-cid'...
>>> Saving state... (CID: 9)
>>> Saving state... (PDH: 1205534464)
>>> Network started successfully
>>>
>>> #qmicli -d /dev/cdc-wdm0 --get-service-version-info
>>> [   79.644073] qmi_wwan 1-1:1.8: nonzero urb status received: -EPIPE
>>> [10 Mar 2014, 20:22:03] -Warning ** Error reading from istream: Error
>>> reading from file descriptor: Input/output error
>>>
>>> error: couldn't get service version info: Transaction timed out
>>
>> Hmm, wonder if that isn't a symptom of a firmware crash maybe?
>
> After seeing error message,  the system is frozen without any kernel
> panic/oops msg.
> (ping is available but other service such like ssh is unavailable)

OK, that sounds like we end up in a busy loop somewhere. Are you testing
this on a single core system?

> I'll keep trace on communication protocol between module and qmi_wwan.

I'll try to figure out how we can end up looping at this point. It does
look like it is related to the status endpoint handling, so it is
probably in the cdc-wdm driver somewhere.  We have changed that driver
somewhat for v3.13, but I don't think any of the changes would fix a bug
like this. It would still be useful to know if you can recreate the
problem on v3.13.2 or later, if that is something you easily can do.




Bjørn