Huawei E820W MBIM issue

[Aleksander Morgado]

On Tue, Jun 10, 2014 at 4:29 PM, Aleksander Morgado
<aleksander at aleksander.es> wrote:
> On Tue, Jun 10, 2014 at 4:12 PM, Dan Williams <dcbw at redhat.com> wrote:
>> Causes the device caps query to fail, and the device ends up with "none"
>> capabilities.  Any ideas what's going on?  MM from git master today,
>> libmbim from May 27th.  Looks like MM is receiving an unexpected
>> message?
>>
>> Dan
>>
>
> That is weird.... see below.
>
>
>> ModemManager[2074]: [/dev/cdc-wdm0] Queried max control message size:
>> 1536
>
>
> So, you send a MBIM Open message (transaction 1)....
>
>> ModemManager[2074]: [/dev/cdc-wdm0] Sent message...
>> <<<<<< RAW:
>> <<<<<<   length = 16
>> <<<<<<   data   = 01:00:00:00:10:00:00:00:01:00:00:00:00:06:00:00
>> ModemManager[2074]: [/dev/cdc-wdm0] Sent message (translated)...
>> <<<<<< Header:
>> <<<<<<   length      = 16
>> <<<<<<   type        = open (0x00000001)
>> <<<<<<   transaction = 1
>> <<<<<< Contents:
>> <<<<<<   max_control_transfer = 1536
>
>
> And you get the MBIM Open Done reply (for transaction 1)....
>
>> ModemManager[2074]: [/dev/cdc-wdm0] Received message...
>>>>>>>> RAW:
>>>>>>>>   length = 16
>>>>>>>>   data   = 01:00:00:80:10:00:00:00:01:00:00:00:00:00:00:00
>> ModemManager[2074]: <debug> [1402407677.718576]
>> [mm-broadband-modem-mbim.c:1281] parent_initialization_started_ready():
>> Couldn't start parent initialization: Couldn't open ports during modem
>> initialization: Couldn't get primary port
>> ModemManager[2074]: <debug> [1402407677.718936]
>> [mm-broadband-modem-mbim.c:210] modem_load_current_capabilities():
>> loading current capabilities...
>
> And you think you're good to go as the Open is ready, so you send a
> new MBIM request (transaction 2)....
>
>> ModemManager[2074]: [/dev/cdc-wdm0] Sent message...
>> <<<<<< RAW:
>> <<<<<<   length = 48
>> <<<<<<   data   =
>> 03:00:00:00:30:00:00:00:02:00:00:00:01:00:00:00:00:00:00:00:A2:89:CC:33:BC:BB:8B:4F:B6:B0:13:3E:C2:AA:E6:DF:01:00:00:00:00:00:00:00:00:00:00:00
>> ModemManager[2074]: [/dev/cdc-wdm0] Sent message (translated)...
>> <<<<<< Header:
>> <<<<<<   length      = 48
>> <<<<<<   type        = command (0x00000003)
>> <<<<<<   transaction = 2
>> <<<<<< Fragment header:
>> <<<<<<   total   = 1
>> <<<<<<   current = 0
>> <<<<<< Contents:
>> <<<<<<   service =
>> 'basic-connect' (a289cc33-bcbb-8b4f-b6b0-133ec2aae6df)
>> <<<<<<   cid     = 'device-caps' (0x00000001)
>> <<<<<<   type    = 'query' (0x00000000)
>
>
> And, hey, you get yet another Open Done message for transaction 1; ok,
> we can discard this one...
>
>> ModemManager[2074]: [/dev/cdc-wdm0] Received message...
>>>>>>>> RAW:
>>>>>>>>   length = 16
>>>>>>>>   data   = 01:00:00:80:10:00:00:00:01:00:00:00:00:00:00:00
>> ModemManager[2074]: [/dev/cdc-wdm0] No transaction matched in received
>> message
>
> But wtf, you still get yet another Open Done message, this time for
> transaction 2?
>
>> ModemManager[2074]: [/dev/cdc-wdm0] Received message...
>>>>>>>> RAW:
>>>>>>>>   length = 16
>>>>>>>>   data   = 01:00:00:80:10:00:00:00:02:00:00:00:00:00:00:00
>> ModemManager[2074]: mbim_message_command_done_get_result: assertion
>> 'MBIM_MESSAGE_GET_MESSAGE_TYPE (self) == MBIM_MESSAGE_TYPE_COMMAND_DONE'
>> failed
>
> I don't think I've covered this case in libmbim, truth be told. We
> should definitely check if the request we expect matches not only
> transaction ID but also the request type that we expect.
>
> Don't know why this modem does this, though...
>


Pushed a patch to handle this issue to git master; Dan tested it already.

Cheers!

-- 
Aleksander
https://aleksander.es