MC7455 on 19.07.2, using QMI

[reinerotto]

I exchanged a working EC25 (using serial 3g) on a ZBT-WE826 with a MC7455, trying to get more speed.
Using the same SIM, which worked with the EC25.
However, the MC7455 can not connect to the carrier.
I see
uqmi -d /dev/cdc-wdm0 --get-serving-system
{
"registration": "registered",
"plmn_mcc": 310,
"plmn_mnc": 260,
"plmn_description": "T-Mobile",
"roaming": false
}
I also see wwan0 in ifconfig, but I do not get an IP.
Having checked here on the forum, I have seen other older posts stating similar problem.
Has anybody running the MC7455, using QMI, on 19.07.2 ?
If yes, setup done according to
https://openwrt.org/docs/guide-user/network/wan/wwan/ltedongle
or any special procedure ?

[AndrewZ]

consider using this OpenWrt-based firmware

[reinerotto]

Thanx for replying. As I have seen, it is based on 18.06. Which might be a bit outdated regarding other drivers for MT7620-based devices. I do not want to trade one issue with another But I will keep it in mind as last resort.

[s4ndm4n]

Yeah he also recommended this Firmware to me..
But i have the same mind as you..
Want to be up to date.

And also there have to be a way to get it working if it works in that firmware which is based on OpenWRT.

Also i dont think the goal of this forum and the OpenWRT community is, to redirect to other OpenWRT based build..

We need to fix it here in the official OpenWRT firmware to improve this lovely peace of a router firmware more and more

[reinerotto]

@s4ndm4n

And also there have to be a way to get it working if it works in that firmware which is based on OpenWRT.

The question would be, which driver is used over there. As there is older MBIM, which is supposed even to work with older kernels. Or Serial. Which I am about to try.

[bmork]

@reinerotto

I see
uqmi -d /dev/cdc-wdm0 --get-serving-system
{
"registration": "registered",
"plmn_mcc": 310,
"plmn_mnc": 260,
"plmn_description": "T-Mobile",
"roaming": false
}

well, that looks fine, doesn't it? Why do you believe you can't connect?

@reinerotto

I also see wwan0 in ifconfig, but I do not get an IP.

You don't get an IP. You need to configure it somehow. DHCP might be supported, but there is no guarantee. I don't remember if it is supported on the MC7455. But I recommend using QMI to retrieve the IP config, and then configure the netdev according to that.

And don't ever use autoconnect as described on that page. You need to disable that if you've turned it on

[xback]

Please make sure you update the modem to the latest firmware.

I also have one of these in the field here and without a recent version it was working very bad:

• qmi connect fails sometimes
• sim detect issues
• sudden reboots
• wrong AT output or out-of-sync
• ...

To obtain the firmware, you can make a free account on the Sierra website.

The easiest way is to just download the Windows update binary and let it run.

[reinerotto]

Just to be on the safe side, could you please provide the relevant part of /etc/config/network for wwan ?
and the uqmi-cmds, you use, to setup the connection with the MC7455 ?
I only got it working once, just by chance, probably, because not reproducable.

[s4ndm4n]

Which packages did you have installed?

Make:

opkg list-installed

[pj0e]

check here I hade the same problem APU 4 and Sierra Wireless MC7455 in QMI-mode

[reinerotto]

I have a custom build, all packages built-in. And now, while trying various methods to get the MC7455 up and running, I installed practically everything. Actually now Im trying to use modemmanager.
Anyway, lsmod:

...
slhc                    5243  1 ppp_generic
udp_tunnel              2767  1 wireguard
usb_common              2551  1 usbcore
usb_wwan                4647  1 qcserial
usbcore               132195 11 qcserial,usb_wwan,qmi_wwan,usbserial,usbnet,cdc_wdm,ohci_platform,ohci_hcd,ehci_platform,ehci_hcd
usbnet                 18037  1 qmi_wwan
usbserial              18603  2 qcserial,usb_wwan

From dmesg:

Fri Apr 24 06:04:20 2020 kern.info kernel: [   13.960897] qmi_wwan 1-1.2:1.8: cdc-wdm0: USB WDM device
Fri Apr 24 06:04:20 2020 kern.info kernel: [   13.992155] qmi_wwan 1-1.2:1.8 wwan0: register 'qmi_wwan' at usb-101c0000.ehci-1.2, WWAN/QMI device,
Fri Apr 24 06:04:20 2020 kern.info kernel: [   14.037458] qmi_wwan 1-1.2:1.10: cdc-wdm1: USB WDM device
Fri Apr 24 06:04:20 2020 kern.info kernel: [   14.044264] qmi_wwan 1-1.2:1.10 wwan1: register 'qmi_wwan' at usb-101c0000.ehci-1.2, WWAN/QMI device,
Fri Apr 24 06:04:20 2020 kern.info kernel: [   14.055614] usbcore: registered new interface driver qmi_wwan
Fri Apr 24 06:04:20 2020 kern.info kernel: [   14.188608] usbcore: registered new interface driver qcserial
Fri Apr 24 06:04:20 2020 kern.info kernel: [   14.194626] usbserial: USB Serial support registered for Qualcomm USB modem
Fri Apr 24 06:04:20 2020 user.err kernel: [   14.221193] urngd: jent-rng init failed, err: 2
Fri Apr 24 06:04:20 2020 kern.info kernel: [   14.247545] qcserial 1-1.2:1.0: Qualcomm USB modem converter detected
Fri Apr 24 06:04:20 2020 kern.info kernel: [   14.254501] usb 1-1.2: Qualcomm USB modem converter now attached to ttyUSB0
Fri Apr 24 06:04:20 2020 kern.info kernel: [   14.291252] qcserial 1-1.2:1.2: Qualcomm USB modem converter detected
Fri Apr 24 06:04:20 2020 kern.info kernel: [   14.298291] usb 1-1.2: Qualcomm USB modem converter now attached to ttyUSB1
Fri Apr 24 06:04:20 2020 kern.info kernel: [   14.315477] qcserial 1-1.2:1.3: Qualcomm USB modem converter detected
Fri Apr 24 06:04:20 2020 kern.info kernel: [   14.322561] usb 1-1.2: Qualcomm USB modem converter now attached to ttyUSB2

.config:

CONFIG_PACKAGE_kmod-usb-net-qmi-wwan=y
CONFIG_PACKAGE_kmod-usb-serial-wwan=y
CONFIG_PACKAGE_wwan=y
CONFIG_PACKAGE_kmod-usb-serial=y
CONFIG_PACKAGE_kmod-usb-serial-qualcomm=y

[reinerotto]

No. Should it ? If yes, whats the purpose of it, as I am using the MC7455 integrated into the ZBT-826.

[bmork]

@s4ndm4n

Usb-modeswitch

usb-modeswitch is neither necessary nor useful for MC7455, and most other mini-PCIe or m.2 modules. They are configured as modems by default.

[bmork]

well, that looks fine too. I'm still wondering what part isn't working. You've only posted examples of stuff that seems to be working as intended. I have seen the "I do not get an IP", but I have a feeling that is caused by an expectation mismatch.

Anyway, using ModemManager should work out-of-the-box. The only hard problem is getting the device path right. I recommend looking it up with mmcli as suggested on https://openwrt.org/docs/guide-user/network/wan/wwan/modemmanager

FWIW, this is my config for a QMI configured EM7565 connected to the USB3 port of a Linksys WRT1900v1:

config interface 'mm'
        option device '/sys/devices/platform/soc/soc:pcie@82000000/pci0000:00/0000:00:01.0/0000:01:00.0/usb3/3-2'
        option proto 'modemmanager'
        option apn 'internet.public'
        option pincode '1234'
        option iptype 'ipv4'

The device path can be quite ugly as this demonstrates. The WRT1900v1 has a PCIe connected EJ168 xhci controller, so you have the whole soc->pcie->usb->modem chain there.

[tchouca]

Hi! Did you have any idea for a similar problem ? Thanks

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