Sierra MC7354

[szlin]

2014-03-11 16:47 GMT+08:00 Bjørn Mork <bjorn at mork.no>:
> 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?
>

This module is embedded in a device.
Single QMI configuration with one QMI interface - /dev/cdc-wdm0 (I
think it is weird?)


>
>>>> 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?
>

Yes, 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.
>
>

Thanks for your advice.

By the way, I have tried kernel 3.2(port from 3.4)  & 3.12, both are
failed. (port 3.13 need a lot of effort.)

my suspection is - MC7354 module should have more than one interface,
and I am working on it.

>
>
> Bjørn