Sierra Wireless AirPrime EM919X support

[Loic Poulain]

HI Thomas,

On Tue, 7 Sept 2021 at 10:20, Thomas Perrot <thomas.perrot at bootlin.com> wrote:
>
> Hello,
>
> I still have some issues driving the Sierra Wireless AirPrime EM919X
> with ModemManager.
>
> Now, the modem is detected, but it is stuck in "unavailable" status and
> ModemManager fails to communicate with it through QMI, do you have any
> idea of what I should check?
>
> Moreover, I tried to increase the timeout value, I have also tried to
> disable MBIM, because EM919X exposes a QMI and a MBIM interface, then
> when the MBIM interface is available MM try to use QMI over MBIM, after
> failure with QMI and, in this case, the message "mhi_wwan_ctrl
> mhi0_QMI: Failed to queue buffer" is raised.

Which kernel tag/commit are you building from? would you be able to
try on mainline.

I don't know much about this modem, but some vendors support the MBIM
way, the QMI way, or both. The modem has the generic SDX55 PCI ids and
is then exposing both, maybe this is not the right thing for this
modem. I would suggest checking if this modem has subvendor-ids, and
add a specific mhi_controller_config structure for it in
mhi/pci_generic, you can try the 'MBIM way' similarly to what has been
done for modem_foxconn_sdx55_config.

Regards,
Loic




mhi_controller_config