EM9291 Sierra Wireless not detected by ModemManager

BadTalent · December 17, 2025, 4:36pm

I am using Verdin IMX8MM/P on a custom carrier board.

I have however also tried on the Mallow Carrier Board and obtain the same results leading me to believe this is solely a Software related issue not hardware related.

I have an issue that i have been working over.

I have a requirement to use the Sierra Wireless EM9291. The modem is detected through PCI. however is not attaching to ModemManager.

It is detected with lspsci:

01:00.0 Unassigned class [ff00]: Qualcomm Technologies, Inc Device 0308 	Subsystem: Qualcomm Technologies, Inc Device 0308 	Flags: fast devsel, IRQ 216 	Memory at 18100000 (64-bit, non-prefetchable) [disabled] [size=4K] 	Memory at 18101000 (64-bit, non-prefetchable) [disabled] [size=4K] 	Capabilities: [40] Power Management version 3 	Capabilities: [50] MSI: Enable- Count=1/32 Maskable+ 64bit+ 	Capabilities: [70] Express Endpoint, IntMsgNum 0 	Capabilities: [100] Advanced Error Reporting 	Capabilities: [148] Secondary PCI Express 	Capabilities: [168] Physical Layer 16.0 GT/s <?> 	Capabilities: [18c] Lane Margining at the Receiver 	Capabilities: [19c] Transaction Processing Hints 	Capabilities: [228] Latency Tolerance Reporting 	Capabilities: [230] L1 PM Substates 	Capabilities: [240] Data Link Feature <?> 	Kernel driver in use: mhi-pci-generic

seen with dmesg

[    8.154971] imx6q-pcie 33800000.pcie: host bridge /soc@0/pcie@33800000 ranges:
[    8.155029] imx6q-pcie 33800000.pcie:       IO 0x001ff80000..0x001ff8ffff -> 0x0000000000
[    8.155047] imx6q-pcie 33800000.pcie:      MEM 0x0018000000..0x001fefffff -> 0x0018000000
[    8.401750] imx6q-pcie 33800000.pcie: iATU: unroll T, 4 ob, 4 ib, align 64K, limit 4G
[    8.501587] imx6q-pcie 33800000.pcie: PCIe Gen.1 x1 link up
[    8.601557] imx6q-pcie 33800000.pcie: PCIe Gen.2 x1 link up
[    8.601585] imx6q-pcie 33800000.pcie: Link up, Gen2
[    8.601592] imx6q-pcie 33800000.pcie: PCIe Gen.2 x1 link up
[    8.602092] imx6q-pcie 33800000.pcie: PCI host bridge to bus 0000:00
[    8.602106] pci_bus 0000:00: root bus resource [bus 00-ff]
[    8.602115] pci_bus 0000:00: root bus resource [io  0x0000-0xffff]
[    8.602121] pci_bus 0000:00: root bus resource [mem 0x18000000-0x1fefffff]
[    8.602150] pci 0000:00:00.0: [16c3:abcd] type 01 class 0x060400
[    8.602165] pci 0000:00:00.0: reg 0x10: [mem 0x00000000-0x000fffff]
[    8.602176] pci 0000:00:00.0: reg 0x38: [mem 0x00000000-0x0000ffff pref]
[    8.602226] pci 0000:00:00.0: supports D1
[    8.602231] pci 0000:00:00.0: PME# supported from D0 D1 D3hot D3cold
[    8.604082] pci 0000:01:00.0: [17cb:0308] type 00 class 0xff0000
[    8.604148] pci 0000:01:00.0: reg 0x10: [mem 0x00000000-0x00000fff 64bit]
[    8.604190] pci 0000:01:00.0: reg 0x18: [mem 0x00000000-0x00000fff 64bit]
[    8.604548] pci 0000:01:00.0: PME# supported from D0 D3hot D3cold
[    8.604857] pci 0000:01:00.0: 4.000 Gb/s available PCIe bandwidth, limited by 5.0 GT/s PCIe x1 link at 0000:00:00.0 (capable of 15.752 Gb/s with 8.0 GT/s PCIe x2 link)
[    8.641599] pci 0000:00:00.0: BAR 0: assigned [mem 0x18000000-0x180fffff]
[    8.641630] pci 0000:00:00.0: BAR 14: assigned [mem 0x18100000-0x181fffff]
[    8.641639] pci 0000:00:00.0: BAR 6: assigned [mem 0x18200000-0x1820ffff pref]
[    8.641650] pci 0000:01:00.0: BAR 0: assigned [mem 0x18100000-0x18100fff 64bit]
[    8.641685] pci 0000:01:00.0: BAR 2: assigned [mem 0x18101000-0x18101fff 64bit]
[    8.641719] pci 0000:00:00.0: PCI bridge to [bus 01-ff]
[    8.641728] pci 0000:00:00.0:   bridge window [mem 0x18100000-0x181fffff]
[    8.642348] pcieport 0000:00:00.0: PME: Signaling with IRQ 215
[    8.643423] pcieport 0000:00:00.0: AER: enabled with IRQ 215
[    8.643784] mhi-pci-generic 0000:01:00.0: MHI PCI device found: sierra-em919x
[    8.643801] mhi-pci-generic 0000:01:00.0: BAR 0: assigned [mem 0x18100000-0x18100fff 64bit]
[    8.643852] mhi-pci-generic 0000:01:00.0: enabling device (0000 -> 0002)
[    8.653929] mhi mhi0: Requested to power ON
[   12.371812] mhi mhi0: Power on setup success
[   12.372032] mhi mhi0: Wait for device to enter SBL or Mission mode
[   12.428819] wwan wwan0: port wwan0qcdm0 attached
[   12.429128] wwan wwan0: port wwan0mbim0 attached
[   12.429333] wwan wwan0: port wwan0qmi0 attached
[   12.437112] wwan wwan0: port wwan0at0 attached
[  326.577371] mhi-pci-generic 0000:01:00.0: Unable to change power state from D3hot to D0, device inaccessible
[  326.587291] mhi mhi0: Resuming from non M3 state (SYS ERROR)
[  326.587300] mhi-pci-generic 0000:01:00.0: failed to resume device: -22
[  326.593847] mhi-pci-generic 0000:01:00.0: device recovery started
[  326.593987] wwan wwan0: port wwan0qcdm0 disconnected
[  326.595469] mhi_wwan_ctrl mhi0_MBIM: Failed to queue buffer
[  326.601097] mhi_wwan_ctrl mhi0_MBIM: Failed to queue buffer
[  326.610828] wwan wwan0: port wwan0mbim0 disconnected
[  326.611344] wwan wwan0: port wwan0qmi0 disconnected
[  326.612393] wwan wwan0: port wwan0at0 disconnected
[  326.627567] mhi mhi0: Requested to power ON
[  326.627615] mhi mhi0: Power on setup success
[  350.805467] mhi-pci-generic 0000:01:00.0: reset
[  353.037937] mhi mhi0: Requested to power ON
[  355.045424] mhi mhi0: Power on setup success
[  355.045514] mhi mhi0: Wait for device to enter SBL or Mission mode

but not with ModemManager. I have enabled debug mode on ModemManager and see the following output:

Dec 17 12:54:10 06944405 ModemManager[454]: <dbg> [1765976050.311931] [plugin/generic] probes required for port wwan0qmi0: 'at, qcdm, qmi, mbim'
Dec 17 12:54:10 06944405 ModemManager[454]: <dbg> [1765976050.311960] [wwan0qmi0/probe] no AT/QCDM/MBIM probing in possible QMI port
Dec 17 12:54:10 06944405 ModemManager[454]: <dbg> [1765976050.311979] [wwan0qmi0/probe] port is not AT-capable
Dec 17 12:54:10 06944405 ModemManager[454]: <dbg> [1765976050.311997] [wwan0qmi0/probe] port is not QCDM-capable
Dec 17 12:54:10 06944405 ModemManager[454]: <dbg> [1765976050.312014] [wwan0qmi0/probe] port is not MBIM-capable
Dec 17 12:54:10 06944405 ModemManager[454]: <dbg> [1765976050.312032] [wwan0qmi0/probe] port probing finished: no more probings needed
Dec 17 12:54:10 06944405 ModemManager[454]: <dbg> [1765976050.312082] [plugin-manager] task 1,wwan0qmi0: found best plugin for port (generic)
Dec 17 12:54:10 06944405 ModemManager[454]: <dbg> [1765976050.312105] [plugin-manager] task 1,wwan0qmi0: finished in '48.350582' seconds
Dec 17 12:54:10 06944405 ModemManager[454]: <dbg> [1765976050.312145] [plugin-manager] task 1,wwan0qmi0: best plugin matches device reported one: generic
Dec 17 12:54:10 06944405 ModemManager[454]: <dbg> [1765976050.312167] [plugin-manager] task 1: no more ports to probe
Dec 17 12:54:10 06944405 ModemManager[454]: <dbg> [1765976050.312186] [plugin-manager] task 1: finished in '48.377354' seconds
Dec 17 12:54:10 06944405 ModemManager[454]: <msg> [1765976050.312247] [device /sys/devices/platform/soc@0/33800000.pcie/pci0000:00/0000:00:00.0/0000:01:00.0] creating modem with plugin 'generic' and '4' ports
Dec 17 12:54:10 06944405 ModemManager[454]: <dbg> [1765976050.312283] [plugin/generic] (generic) MBIM-powered generic modem found...
Dec 17 12:54:10 06944405 ModemManager[454]: <wrn> [1765976050.324987] [plugin/generic] could not grab port wwan0at0: Cannot add port 'wwan/wwan0at0', unhandled port type
Dec 17 12:54:10 06944405 ModemManager[454]: <wrn> [1765976050.325100] [plugin/generic] could not grab port wwan0qmi0: Cannot add port 'wwan/wwan0qmi0', unhandled port type
Dec 17 12:54:10 06944405 ModemManager[454]: <dbg> [1765976050.325173] [wwan0mbim0/mbim] port monitoring enabled in MBIM port
Dec 17 12:54:10 06944405 ModemManager[454]: <dbg> [1765976050.325240] [modem0] port 'wwan/wwan0mbim0' grabbed
Dec 17 12:54:10 06944405 ModemManager[454]: <dbg> [1765976050.325270] [plugin/generic] port wwan0qcdm0 is explicitly ignored
Dec 17 12:54:10 06944405 ModemManager[454]: <dbg> [1765976050.325312] [modem0] port 'wwan/wwan0qcdm0' grabbed
Dec 17 12:54:10 06944405 ModemManager[454]: <dbg> [1765976050.325351] [modem0] supported notifications: signal (no), registration (no), sms (no), connect (no), subscriber (no), packet (no), pco (no), ussd (no), lte attach info (no), provisioned contexts (no), slot_info_status (no)
Dec 17 12:54:10 06944405 ModemManager[454]: <dbg> [1765976050.325418] [modem0] cleaning up port 'unknown/wwan0qcdm0'...
Dec 17 12:54:10 06944405 ModemManager[454]: <dbg> [1765976050.325445] [modem0] cleaning up port 'wwan/wwan0mbim0'...
Dec 17 12:54:10 06944405 ModemManager[454]: <dbg> [1765976050.325529] [modem0] completely disposed
Dec 17 12:54:10 06944405 ModemManager[454]: <wrn> [1765976050.325562] [base-manager] couldn't create modem for device '/sys/devices/platform/soc@0/33800000.pcie/pci0000:00/0000:00:00.0/0000:01:00.0': Failed to find a net port in the MBIM modem

Any Guidence on having ModemManager be able to work alongside the Modem would be appreciated.

ToradexAI · December 17, 2025, 4:36pm

Hi, I’m the Toradex AI Assistant.

I might make mistakes or occasionally get you wrong. Our support team will step in if needed.

To help you get the most accurate guidance, could you let me know which OS and version you’re using? You can get this information by running the tdx-info command on your device. This will help me provide more specific troubleshooting steps for your setup.

For reference on getting system information, please see: tdx-info command documentation

Based on your logs and the error messages you’re seeing, this appears to be a ModemManager configuration issue specific to how the Sierra EM9291 ports are being handled. The key error is:

Failed to find a net port in the MBIM modem

Analysis of Your Issue

Your modem is being detected correctly by the MHI (Modem Host Interface) driver and creating the expected WWAN ports (1). However, ModemManager is failing to properly handle the port configuration for this specific modem model.

ModemManager Support

ModemManager is available on Torizon OS out-of-the-box and provides support for mobile broadband devices through the mmcli command-line tool (1). ModemManager uses libqmi and libmbim to communicate over Qualcomm MSM Interface (QMI) and Mobile Interface Broadband Model (MBIM) protocols (1).

Troubleshooting Steps

1. Check Port Detection

First, verify which ports are actually available:

ls -la /dev/wwan*

2. Manual ModemManager Configuration

Try restarting ModemManager with additional debugging:

systemctl stop ModemManager
ModemManager --debug --log-level=DEBUG

3. Check Network Interface

The error suggests ModemManager cannot find the network interface. Check if a network interface was created:

ip link show | grep wwan

Sierra EM9291 Compatibility

Based on community discussions, the Sierra EM9291 is not officially listed as a compatible peripheral for Toradex modules (2). The modem detection issues you’re experiencing have been reported by other users, where the device is detected via PCIe but fails to properly enumerate with ModemManager (2).

Alternative Approaches

1. Custom Device Tree Configuration

Since this modem isn’t officially supported, you may need custom device tree overlays to properly configure the PCIe interface and port mappings.

2. Manual Port Configuration

You might need to manually configure the WWAN ports or create udev rules to properly map the device interfaces.

3. Consider Supported Alternatives

For production use, consider using modems from the Peripheral Database that have been tested with Toradex modules (3).

Once you provide your OS version information, I can give you more specific guidance for your platform.

Best regards, Toradex AI Assistant.

Did you like my answer?

If I answered your question, please tick the “Solution” checkbox.

For follow-up questions to me, please use @ToradexAI in your post.

joaom.tx · December 18, 2025, 11:24am

Hello @BadTalent !

The hardware and PCIe side looks correct and the issue seems to be that ModemManager cannot find a valid network interface associated with the modem.

The first would be to do is connecting to the AT port wwan0at0, unlock the modem with AT!ENTERCND="A710", check the current USB composition with AT!USBCOMP?, and then force a supported composition such as MBIM using AT!USBCOMP=1,1,<pid>.

Restart it, and once the system comes back up, it should appear with ip link.