wda-get-data-format randomly returns error: couldn't create client for the 'wda' service

[Tor Rune Skoglund]

Hi Aleksander,

tir. 31. mar. 2020 kl. 05:43 skrev Aleksander Morgado <
aleksander at aleksander.es>:

> Hey Tor,
>
> >
> > I am experiencing a very strange problem with MC7304. Randomly (like in
> 1 of 3 instances), when initializing the WAN connection, the modem setup
> routine fails on the --wda-get-data-format command, and then the completion
> of the initialization just fails. For now, we have just been detecting this
> and then reset the usb port and rerun the whole procedure at regular
> intervals until it works, but that is not a permanent solution. The
> wda-set-data-format also fails when get does.
> >
> > Have been googling 'lightly' without any obvious success. I was hoping
> some of you experts on this list just pops up and say 'you need to do this'
> before we start spending to much on digging very deeply into the issue :)
> >
> > # qmicli -d /dev/cdc-wdm0 --wda-get-data-format
> > error: couldn't create client for the 'wda' service: QMI protocol error
> (3): 'Internal'
> >
> > libqmi version: 1.22.2
> >
> > kernel 4.9.199
> >
> > MC7304 firmware:
> > Model: MC7304
> >         Boot version: SWI9X15C_05.05.78.00 r34310 CARMD-EV-FRMWR3
> 2017/09/17 00:43:17
> >         AMSS version: SWI9X15C_05.05.78.00 r34310 CARMD-EV-FRMWR3
> 2017/09/17 00:43:17
> >         SKU ID: 1103054
> >         Package ID:
> 1103054_9906141_MC7304_05.05.66.00_00_Generic_005.000_000
> >         Carrier ID: 1
> >         Config version: 005.029_000
> >
> > Any hints or advises appreciated.
>

I have some further updates here. I read another thread about the '-p'
option,
which, when added to all instances of qmicli invocation in the init.d file
makes
the problem go away in at least more than 9 out of 10 cases. So it is
apparently a timing issue. Still have to test this on more than one
system, but I am optimistic. :)


> Nothing from the top of my head really.
>
> Is this happening only during boot? Maybe you didn't wait long enough
> to boot before sending the WDA command?
>

It seems that it happens randomly both at boot and after boot. And 'boot'
in this case
is actually a minute or so after power is applied.


> Are you only sending the WDA command, or some other additional
> commands as well? Are those commands failing or is it only the WDA
> service?
>

We check the output of the wda-get-data-format command, and depending on
that, other commands will run - like putting it into 802-3 mode. Other
commands
seem to work anyway, like -w or --wds-get-packet-service-status.

When you say you're reseting the USB port, are you literally just
> reseting the USB comm in your host forcing a re-enumeration of the
> device? Or are you fully powering off the modem externally and
> powering it back on? Or triggering a rdevice reboot with the DMS
> service?
>

We are sending an unbind and bind to the USB port the modem is connected
to, which forces re-enumeration. But after learning and testing with the -p
option,
I cannot be sure that it really affects anything, or if it worked sometimes
just
randomly as before.

BR,
Tor Rune Skoglund
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