PCIE mode in new 5G modems

[Aleksander Morgado]

Hey Bruno,

> Has anyone tried the PCIE mode on the newer 5G modems?

Yes yes, I use one almost everyday in my laptop.

> I have tested with both the Quectel RM500Q and the SIMCom 8202G with no success.
> The Quectel model is detected by the modemmanager but can't establish
> a connection:
>
>
> mmcli -V
> mmcli 1.17.900
>
> mmcli -L
>     /org/freedesktop/ModemManager1/Modem/1 [manufacturer unknown] model unknown
>     /org/freedesktop/ModemManager1/Modem/0 [Quectel] RM500Q-GL
>
> mmcli -m 0
>   -----------------------------
>   General  |              path: /org/freedesktop/ModemManager1/Modem/0
>                  |         device id: 9490a63480fa96a9c2b519059801e65adb2a9681
>   -----------------------------
>   Hardware |      manufacturer: Quectel
>                   |             model: RM500Q-GL
>                   | firmware revision: RM500QGLABR11A03M4G
>                   |         supported: gsm-umts, lte
>                   |           current: gsm-umts, lte
>                   |      equipment id: 863305040265935
>   -----------------------------
>   System   |            device:
> /sys/devices/platform/soc/3110000.usb3/xhci-hcd.1.auto/usb4/4-1/4-1.2

The RM500 here is being detected in USB mode, not in PCI mode.

>                  |           drivers: option

And only used with TTYs, not being managed in either MBIM or QMI. Is
this a custom system that doesn't have qmi_wwan or cdc_mbim support?

>                  |            plugin: quectel
>                  |      primary port: ttyUSB2
>                  |             ports: ttyUSB0 (qcdm), ttyUSB1 (gps),
> ttyUSB2 (at)
>   -----------------------------
>   Status   |              lock: sim-pin
>                |    unlock retries: sim-pin (3), sim-puk (10),
> sim-pin2 (3), sim-puk2 (10)
>                |             state: locked

Here it says the SIM-PIN is locked; did you try to unlock it before
attempting the connection?

>                |       power state: on
>                |    signal quality: 0% (cached)
>   -----------------------------
>   Modes    |         supported: allowed: 2g, 3g, 4g; preferred: none
>                  |           current: allowed: 2g, 3g, 4g; preferred: none
>   -----------------------------
>   IP       |         supported: ipv4, ipv6, ipv4v6
>   -----------------------------
>   3GPP     |     enabled locks: sim
>   -----------------------------
>   SIM      |  primary sim path: /org/freedesktop/ModemManager1/SIM/0
>
>
> mmcli -m 1
>   -------------------------
>   General |           path: /org/freedesktop/ModemManager1/Modem/1
>   -------------------------
>   System  |         device:
> /sys/devices/platform/soc/3400000.pcie/pci0000:00/0000:00:00.0/0000:01:00.0
>                 |        drivers: mhi_net, mhi-pci-generic

This one is PCI, yes.

>                 |         plugin: generic
>                 |   primary port: wwan0qmi0
>                 |          ports: mhi_hwip0 (net), wwan0mbim0 (mbim),
> wwan0qmi0 (qmi)

And we can see both QMI and MBIM ports exposed; which is similar to the EM9191.

>   -------------------------
>   Status  | signal quality: 0% (cached)
>   -------------------------
>   Modes   |      supported: allowed: any; preferred: none
>                 |        current: allowed: any; preferred: none
>
>
> The SIMCom modem also should support the PCIE mode  but the
> modemmanager does not detect it.
>
> lspci
> 04:00.0 Unassigned class [ff00]: Qualcomm Device 0306
>

Oh, so this is yet another manufacturer-branded device that reuses the
Qualcomm vid:pid for the SDX55, same as with the EM919x modules. This
means the SIMCOM device is behing handled by the "generic" SDX55
entry, which may not fit perfectly with what the SIMCOM team expected
from this device. Is there any SIMCOM provided "mhi" driver somewhere
that we could look at to see what kind of setup they expect?

> mmcli -L
> No modems were found
>
> lsusb
> Bus 001 Device 003: ID 05c6:901f Qualcomm, Inc.
>
> mmcli -V
> mmcli 1.18.2
>
> qmicli -V
> qmicli 1.30.2
>
> mbimcli -V
> mbimcli 1.26.0
>
> Is something missing? Is anyone working with this?

It's everything pretty new, and the support for multiple modules is
still ongoing. I've been playing with the EM919x myself for some time
now and we have not found a good configuration for it (yet); although
it's true that the issues I'm seeing on that one could be due to the
specific board I'm testing with, which has some limitations.

-- 
Aleksander
https://aleksander.es