WWAN broken - Sierra EM7455 LTE Modem - No Sim

Hi everyone,
Fedora newbie here:

I chose Fedora for my Thinkpad Yoga 370 and I’ve got everything working except for the LTE modem. It doesn’t recognize the SIM card. The modem works fine and connects to the mobile network under Ubuntu and Windows.

mmcli doesn’t see the SIM.

[florian@fedora ~]$ sudo mmcli -m 0 
  -----------------------------
  General  |              path: /org/freedesktop/ModemManager1/Modem/0
           |         device id: e6c3ede42acb77b9dd996e3a265032bbdc6eceee
  -----------------------------
  Hardware |      manufacturer: Sierra Wireless, Incorporated
           |             model: Sierra Wireless EM7455 Qualcomm Snapdragon X7 LTE-A
           | firmware revision: SWI9X30C_02.33.03.00
           |    carrier config: default
           |      h/w revision: EM7455
           |         supported: gsm-umts, lte
           |           current: gsm-umts, lte
  -----------------------------
  System   |            device: /sys/devices/pci0000:00/0000:00:14.0/usb1/1-2
           |           drivers: cdc_mbim
           |            plugin: sierra
           |      primary port: cdc-wdm0
           |             ports: cdc-wdm0 (mbim), wwp0s20f0u2i12 (net)
  -----------------------------
  Status   |             state: failed
           |     failed reason: sim-missing
           |       power state: low
           |    signal quality: 0% (cached)
  -----------------------------
  Modes    |         supported: allowed: 3g; preferred: none
           |                    allowed: 4g; preferred: none
           |                    allowed: 3g, 4g; preferred: 4g
           |                    allowed: 3g, 4g; preferred: 3g
           |           current: allowed: any; preferred: none
  -----------------------------
  Bands    |         supported: utran-1, utran-3, utran-4, utran-5, utran-8, utran-2, 
           |                    eutran-1, eutran-2, eutran-3, eutran-4, eutran-5, eutran-7, eutran-8, 
           |                    eutran-12, eutran-13, eutran-20, eutran-25, eutran-26, eutran-41
  -----------------------------
  IP       |         supported: ipv4, ipv6, ipv4v6

Strangely enough, qmicli does, though:

[florian@fedora ~]$ sudo qmicli -p -d /dev/cdc-wdm0 --uim-get-slot-status
[/dev/cdc-wdm0] Successfully got slots status
[/dev/cdc-wdm0] 2 physical slots found:
  Physical slot 1:
     Card status: present
     Slot status: active
    Logical slot: 1
           ICCID: unknown
  Physical slot 2:
     Card status: unknown
     Slot status: inactive

I suspect that this is a bug, but I’d really like a workaround. I definitely need the LTE modem.

Output of inxi -Fxmz:

System:
  Kernel: 6.0.15-300.fc37.x86_64 arch: x86_64 bits: 64 compiler: gcc
    v: 2.38-25.fc37 Console: pty pts/0 Distro: Fedora release 37 (Thirty Seven)
Machine:
  Type: Convertible System: LENOVO product: 20JJS0SM00 v: ThinkPad Yoga 370
    serial: <filter>
  Mobo: LENOVO model: 20JJS0SM00 v: SDK0J40697 WIN serial: <filter>
    UEFI: LENOVO v: R0HET60W (1.40 ) date: 06/20/2022
Battery:
  ID-1: BAT0 charge: 37.8 Wh (100.0%) condition: 37.8/51.0 Wh (74.2%)
    volts: 17.0 min: 15.2 model: LGC 01AV432 status: full
  Device-1: apple_mfi_fastcharge model: N/A charge: N/A status: N/A
  Device-2: wacom_battery_0 model: Wacom Pen and multitouch sensor
    charge: 0% status: N/A
Memory:
  RAM: total: 7.51 GiB used: 2.45 GiB (32.7%)
  Array-1: capacity: 32 GiB slots: 2 EC: None max-module-size: 16 GiB
    note: est.
  Device-1: ChannelA-DIMM0 type: DDR4 size: 8 GiB speed: 2133 MT/s
  Device-2: ChannelB-DIMM0 type: no module installed
CPU:
  Info: dual core model: Intel Core i5-7300U bits: 64 type: MT MCP
    arch: Amber/Kaby Lake note: check rev: 9 cache: L1: 128 KiB L2: 512 KiB
    L3: 3 MiB
  Speed (MHz): avg: 598 high: 600 min/max: 400/3500 cores: 1: 595 2: 600
    3: 600 4: 600 bogomips: 21599
  Flags: avx avx2 ht lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx
Graphics:
  Device-1: Intel HD Graphics 620 vendor: Lenovo driver: i915 v: kernel
    arch: Gen-9.5 bus-ID: 00:02.0
  Device-2: Chicony Integrated Camera type: USB driver: uvcvideo
    bus-ID: 1-8:5
  Display: server: X.Org v: 22.1.7 with: Xwayland v: 22.1.7 driver:
    dri: iris gpu: i915 note: X driver n/a resolution: 1920x1080~60Hz
  API: OpenGL v: 4.6 Mesa 22.3.1 renderer: Mesa Intel HD Graphics 620 (KBL
    GT2) direct render: Yes
Audio:
  Device-1: Intel Sunrise Point-LP HD Audio vendor: Lenovo
    driver: snd_hda_intel v: kernel bus-ID: 00:1f.3
  Sound API: ALSA v: k6.0.15-300.fc37.x86_64 running: yes
  Sound Server-1: PulseAudio v: 16.1 running: no
  Sound Server-2: PipeWire v: 0.3.63 running: yes
Network:
  Device-1: Intel Ethernet I219-LM vendor: Lenovo driver: e1000e v: kernel
    port: N/A bus-ID: 00:1f.6
  IF: enp0s31f6 state: down mac: <filter>
  Device-2: Intel Wireless 8265 / 8275 driver: iwlwifi v: kernel
    bus-ID: 04:00.0
  IF: wlp4s0 state: up mac: <filter>
  Device-3: Realtek RTL8153 Gigabit Ethernet Adapter type: USB driver: r8152
    bus-ID: 4-1.1.3:5
  IF: enp62s0u1u1u3 state: down mac: <filter>
  IF-ID-1: wwp0s20f0u2i12 state: down mac: <filter>
Bluetooth:
  Device-1: Intel Bluetooth wireless interface type: USB driver: btusb v: 0.8
    bus-ID: 1-7:4
  Report: rfkill ID: hci0 rfk-id: 2 state: up address: see --recommends
Drives:
  Local Storage: total: 476.94 GiB used: 19.48 GiB (4.1%)
  ID-1: /dev/nvme0n1 vendor: Samsung model: MZVLW512HMJP-000L7
    size: 476.94 GiB temp: 37.9 C
Partition:
  ID-1: / size: 475.34 GiB used: 19.25 GiB (4.0%) fs: btrfs dev: /dev/dm-0
    mapped: luks-d00c6509-fbc8-4cbc-8be7-2a5704513fa1
  ID-2: /boot size: 973.4 MiB used: 224.9 MiB (23.1%) fs: ext4
    dev: /dev/nvme0n1p2
  ID-3: /boot/efi size: 598.8 MiB used: 17.4 MiB (2.9%) fs: vfat
    dev: /dev/nvme0n1p1
  ID-4: /home size: 475.34 GiB used: 19.25 GiB (4.0%) fs: btrfs
    dev: /dev/dm-0 mapped: luks-d00c6509-fbc8-4cbc-8be7-2a5704513fa1
Swap:
  ID-1: swap-1 type: zram size: 7.51 GiB used: 0 KiB (0.0%) dev: /dev/zram0
Sensors:
  System Temperatures: cpu: 66.0 C mobo: N/A
  Fan Speeds (RPM): fan-1: 0
Info:
  Processes: 281 Uptime: 4m Init: systemd target: graphical (5) Compilers:
  gcc: 12.2.1 Packages: 20 note: see --rpm Shell: Bash v: 5.2.9 inxi: 3.3.24

This shows 3 devices but 4 interfaces. The last (IF-ID-1) seems the modem.
What does ‘lspci -nnv’ show for the modem?

Hi Jeff, here’s the output:

[florian@fedora ~]$ sudo lspci -nnv
00:00.0 Host bridge [0600]: Intel Corporation Xeon E3-1200 v6/7th Gen Core Processor Host Bridge/DRAM Registers [8086:5904] (rev 02)
	Subsystem: Lenovo Device [17aa:5061]
	Flags: bus master, fast devsel, latency 0
	Capabilities: [e0] Vendor Specific Information: Len=10 <?>
	Kernel driver in use: skl_uncore

00:02.0 VGA compatible controller [0300]: Intel Corporation HD Graphics 620 [8086:5916] (rev 02) (prog-if 00 [VGA controller])
	Subsystem: Lenovo Device [17aa:5061]
	Flags: bus master, fast devsel, latency 0, IRQ 134
	Memory at f1000000 (64-bit, non-prefetchable) [size=16M]
	Memory at e0000000 (64-bit, prefetchable) [size=256M]
	I/O ports at e000 [size=64]
	Expansion ROM at 000c0000 [virtual] [disabled] [size=128K]
	Capabilities: [40] Vendor Specific Information: Len=0c <?>
	Capabilities: [70] Express Root Complex Integrated Endpoint, MSI 00
	Capabilities: [ac] MSI: Enable+ Count=1/1 Maskable- 64bit-
	Capabilities: [d0] Power Management version 2
	Capabilities: [100] Process Address Space ID (PASID)
	Capabilities: [200] Address Translation Service (ATS)
	Capabilities: [300] Page Request Interface (PRI)
	Kernel driver in use: i915
	Kernel modules: i915

00:08.0 System peripheral [0880]: Intel Corporation Xeon E3-1200 v5/v6 / E3-1500 v5 / 6th/7th/8th Gen Core Processor Gaussian Mixture Model [8086:1911]
	Subsystem: Lenovo Device [17aa:5061]
	Flags: fast devsel, IRQ 255
	Memory at f2348000 (64-bit, non-prefetchable) [disabled] [size=4K]
	Capabilities: [90] MSI: Enable- Count=1/1 Maskable- 64bit-
	Capabilities: [dc] Power Management version 2
	Capabilities: [f0] PCI Advanced Features

00:13.0 Non-VGA unclassified device [0000]: Intel Corporation Sunrise Point-LP Integrated Sensor Hub [8086:9d35] (rev 21)
	Subsystem: Lenovo Device [17aa:5061]
	Flags: bus master, fast devsel, latency 0, IRQ 20
	Memory at f2349000 (64-bit, non-prefetchable) [size=4K]
	Capabilities: [80] Power Management version 3
	Kernel driver in use: intel_ish_ipc
	Kernel modules: intel_ish_ipc

00:14.0 USB controller [0c03]: Intel Corporation Sunrise Point-LP USB 3.0 xHCI Controller [8086:9d2f] (rev 21) (prog-if 30 [XHCI])
	Subsystem: Lenovo Device [17aa:5061]
	Flags: bus master, medium devsel, latency 0, IRQ 126
	Memory at f2320000 (64-bit, non-prefetchable) [size=64K]
	Capabilities: [70] Power Management version 2
	Capabilities: [80] MSI: Enable+ Count=1/8 Maskable- 64bit+
	Kernel driver in use: xhci_hcd

00:14.2 Signal processing controller [1180]: Intel Corporation Sunrise Point-LP Thermal subsystem [8086:9d31] (rev 21)
	Subsystem: Lenovo Device [17aa:5061]
	Flags: fast devsel, IRQ 18
	Memory at f234a000 (64-bit, non-prefetchable) [size=4K]
	Capabilities: [50] Power Management version 3
	Capabilities: [80] MSI: Enable- Count=1/1 Maskable- 64bit-
	Kernel driver in use: intel_pch_thermal
	Kernel modules: intel_pch_thermal

00:16.0 Communication controller [0780]: Intel Corporation Sunrise Point-LP CSME HECI #1 [8086:9d3a] (rev 21)
	Subsystem: Lenovo Device [17aa:5061]
	Flags: bus master, fast devsel, latency 0, IRQ 147
	Memory at f234b000 (64-bit, non-prefetchable) [size=4K]
	Capabilities: [50] Power Management version 3
	Capabilities: [8c] MSI: Enable+ Count=1/1 Maskable- 64bit+
	Kernel driver in use: mei_me
	Kernel modules: mei_me

00:1c.0 PCI bridge [0604]: Intel Corporation Sunrise Point-LP PCI Express Root Port #1 [8086:9d10] (rev f1) (prog-if 00 [Normal decode])
	Subsystem: Lenovo Device [17aa:5061]
	Flags: bus master, fast devsel, latency 0, IRQ 122
	Bus: primary=00, secondary=02, subordinate=02, sec-latency=0
	I/O behind bridge: [disabled] [16-bit]
	Memory behind bridge: f2200000-f22fffff [size=1M] [32-bit]
	Prefetchable memory behind bridge: [disabled] [64-bit]
	Capabilities: [40] Express Root Port (Slot+), MSI 00
	Capabilities: [80] MSI: Enable+ Count=1/1 Maskable- 64bit-
	Capabilities: [90] Subsystem: Lenovo Device [17aa:5061]
	Capabilities: [a0] Power Management version 3
	Capabilities: [100] Advanced Error Reporting
	Capabilities: [140] Access Control Services
	Capabilities: [200] L1 PM Substates
	Capabilities: [220] Secondary PCI Express
	Kernel driver in use: pcieport

00:1c.2 PCI bridge [0604]: Intel Corporation Sunrise Point-LP PCI Express Root Port #3 [8086:9d12] (rev f1) (prog-if 00 [Normal decode])
	Subsystem: Lenovo Device [17aa:5061]
	Flags: bus master, fast devsel, latency 0, IRQ 123
	Bus: primary=00, secondary=04, subordinate=04, sec-latency=0
	I/O behind bridge: [disabled] [16-bit]
	Memory behind bridge: f2100000-f21fffff [size=1M] [32-bit]
	Prefetchable memory behind bridge: [disabled] [64-bit]
	Capabilities: [40] Express Root Port (Slot+), MSI 00
	Capabilities: [80] MSI: Enable+ Count=1/1 Maskable- 64bit-
	Capabilities: [90] Subsystem: Lenovo Device [17aa:5061]
	Capabilities: [a0] Power Management version 3
	Capabilities: [100] Advanced Error Reporting
	Capabilities: [140] Access Control Services
	Capabilities: [200] L1 PM Substates
	Capabilities: [220] Secondary PCI Express
	Kernel driver in use: pcieport

00:1c.4 PCI bridge [0604]: Intel Corporation Sunrise Point-LP PCI Express Root Port #5 [8086:9d14] (rev f1) (prog-if 00 [Normal decode])
	Subsystem: Lenovo Device [17aa:5061]
	Flags: bus master, fast devsel, latency 0, IRQ 124
	Bus: primary=00, secondary=05, subordinate=05, sec-latency=0
	I/O behind bridge: [disabled] [16-bit]
	Memory behind bridge: f2000000-f20fffff [size=1M] [32-bit]
	Prefetchable memory behind bridge: [disabled] [64-bit]
	Capabilities: [40] Express Root Port (Slot+), MSI 00
	Capabilities: [80] MSI: Enable+ Count=1/1 Maskable- 64bit-
	Capabilities: [90] Subsystem: Lenovo Device [17aa:5061]
	Capabilities: [a0] Power Management version 3
	Capabilities: [100] Advanced Error Reporting
	Capabilities: [140] Access Control Services
	Capabilities: [200] L1 PM Substates
	Capabilities: [220] Secondary PCI Express
	Kernel driver in use: pcieport

00:1d.0 PCI bridge [0604]: Intel Corporation Sunrise Point-LP PCI Express Root Port #9 [8086:9d18] (rev f1) (prog-if 00 [Normal decode])
	Subsystem: Lenovo Device [17aa:5061]
	Flags: bus master, fast devsel, latency 0, IRQ 125
	Bus: primary=00, secondary=06, subordinate=3e, sec-latency=0
	I/O behind bridge: 2000-2fff [size=4K] [16-bit]
	Memory behind bridge: f0000000-f01fffff [size=2M] [32-bit]
	Prefetchable memory behind bridge: dc800000-dc9fffff [size=2M] [32-bit]
	Capabilities: [40] Express Root Port (Slot+), MSI 00
	Capabilities: [80] MSI: Enable+ Count=1/1 Maskable- 64bit-
	Capabilities: [90] Subsystem: Lenovo Device [17aa:5061]
	Capabilities: [a0] Power Management version 3
	Capabilities: [100] Advanced Error Reporting
	Capabilities: [140] Access Control Services
	Capabilities: [220] Secondary PCI Express
	Kernel driver in use: pcieport

00:1f.0 ISA bridge [0601]: Intel Corporation Sunrise Point LPC Controller/eSPI Controller [8086:9d4e] (rev 21)
	Subsystem: Lenovo Device [17aa:5061]
	Flags: bus master, medium devsel, latency 0

00:1f.2 Memory controller [0580]: Intel Corporation Sunrise Point-LP PMC [8086:9d21] (rev 21)
	Subsystem: Lenovo Device [17aa:5061]
	Flags: fast devsel
	Memory at f2344000 (32-bit, non-prefetchable) [disabled] [size=16K]

00:1f.3 Audio device [0403]: Intel Corporation Sunrise Point-LP HD Audio [8086:9d71] (rev 21)
	Subsystem: Lenovo Device [17aa:5061]
	Flags: bus master, fast devsel, latency 64, IRQ 149
	Memory at f2340000 (64-bit, non-prefetchable) [size=16K]
	Memory at f2330000 (64-bit, non-prefetchable) [size=64K]
	Capabilities: [50] Power Management version 3
	Capabilities: [60] MSI: Enable+ Count=1/1 Maskable- 64bit+
	Kernel driver in use: snd_hda_intel
	Kernel modules: snd_hda_intel, snd_soc_skl, snd_soc_avs

00:1f.4 SMBus [0c05]: Intel Corporation Sunrise Point-LP SMBus [8086:9d23] (rev 21)
	Subsystem: Lenovo Device [17aa:5061]
	Flags: medium devsel, IRQ 16
	Memory at f234c000 (64-bit, non-prefetchable) [size=256]
	I/O ports at efa0 [size=32]
	Kernel driver in use: i801_smbus
	Kernel modules: i2c_i801

00:1f.6 Ethernet controller [0200]: Intel Corporation Ethernet Connection (4) I219-LM [8086:15d7] (rev 21)
	Subsystem: Lenovo Device [17aa:224f]
	Flags: bus master, fast devsel, latency 0, IRQ 128
	Memory at f2300000 (32-bit, non-prefetchable) [size=128K]
	Capabilities: [c8] Power Management version 3
	Capabilities: [d0] MSI: Enable+ Count=1/1 Maskable- 64bit+
	Capabilities: [e0] PCI Advanced Features
	Kernel driver in use: e1000e
	Kernel modules: e1000e

02:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. RTS522A PCI Express Card Reader [10ec:522a] (rev 01)
	Subsystem: Lenovo Device [17aa:5061]
	Flags: bus master, fast devsel, latency 0, IRQ 127
	Memory at f2200000 (32-bit, non-prefetchable) [size=4K]
	Capabilities: [40] Power Management version 3
	Capabilities: [50] MSI: Enable+ Count=1/1 Maskable- 64bit+
	Capabilities: [70] Express Endpoint, MSI 00
	Capabilities: [100] Advanced Error Reporting
	Capabilities: [140] Device Serial Number 00-00-00-01-00-4c-e0-00
	Capabilities: [150] Latency Tolerance Reporting
	Capabilities: [158] L1 PM Substates
	Kernel driver in use: rtsx_pci
	Kernel modules: rtsx_pci

04:00.0 Network controller [0280]: Intel Corporation Wireless 8265 / 8275 [8086:24fd] (rev 88)
	Subsystem: Intel Corporation Device [8086:0130]
	Flags: bus master, fast devsel, latency 0, IRQ 148
	Memory at f2100000 (64-bit, non-prefetchable) [size=8K]
	Capabilities: [c8] Power Management version 3
	Capabilities: [d0] MSI: Enable+ Count=1/1 Maskable- 64bit+
	Capabilities: [40] Express Endpoint, MSI 00
	Capabilities: [100] Advanced Error Reporting
	Capabilities: [140] Device Serial Number 00-28-f8-ff-ff-57-d8-b6
	Capabilities: [14c] Latency Tolerance Reporting
	Capabilities: [154] L1 PM Substates
	Kernel driver in use: iwlwifi
	Kernel modules: iwlwifi

05:00.0 Non-Volatile memory controller [0108]: Samsung Electronics Co Ltd NVMe SSD Controller SM961/PM961/SM963 [144d:a804] (prog-if 02 [NVM Express])
	Subsystem: Samsung Electronics Co Ltd SM963 2.5" NVMe PCIe SSD [144d:a801]
	Flags: bus master, fast devsel, latency 0, IRQ 16, NUMA node 0
	Memory at f2000000 (64-bit, non-prefetchable) [size=16K]
	Capabilities: [40] Power Management version 3
	Capabilities: [50] MSI: Enable- Count=1/32 Maskable- 64bit+
	Capabilities: [70] Express Endpoint, MSI 00
	Capabilities: [b0] MSI-X: Enable+ Count=8 Masked-
	Capabilities: [100] Advanced Error Reporting
	Capabilities: [148] Device Serial Number 00-00-00-00-00-00-00-00
	Capabilities: [158] Power Budgeting <?>
	Capabilities: [168] Secondary PCI Express
	Capabilities: [188] Latency Tolerance Reporting
	Capabilities: [190] L1 PM Substates
	Kernel driver in use: nvme
	Kernel modules: nvme

lspci does not even show the modem. Is it by chance a usb device?
If it is then please show us the output of lsusb -v, but please only post the portion relative to the modem.

If it is not a usb device then I hope someone else has a clue. It really seems there should be a driver that is not being activated.

There was a similar issue recently about a snapdragon modem on a dell laptop that had a solution

Hello Jeff V,

I finally got my issue resolved temporarily in the thread you referenced above. I had to override rpm-ostree override replace .rpm the ModemManager, and qmi packages due to this being Silverblue. These packages will not update going forward once overridden.

Here is the bug report over on Redhat Bugzilla.

https://bugzilla.redhat.com/show_bug.cgi?id=2144732

The packages are over on COPR

https://copr.fedorainfracloud.org/coprs/dcavalca/ModemManager/

There they posted a link to the four packages needed. All they have to do at this point is ship the version numbers to the maintainer, but there is a problem with responsiveness. If OP chooses to override the packages they will have to be reverted, once the updated packages are in the Fedora repository, revert before accepting the update from the repository.

Alright, luckily (?) there is some relevant output.

Bus 001 Device 010: ID 1199:9079 Sierra Wireless, Inc. EM7455
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               2.00
  bDeviceClass            0 
  bDeviceSubClass         0 
  bDeviceProtocol         0 
  bMaxPacketSize0        64
  idVendor           0x1199 Sierra Wireless, Inc.
  idProduct          0x9079 EM7455
  bcdDevice            0.06
  iManufacturer           1 Sierra Wireless, Incorporated
  iProduct                2 Sierra Wireless EM7455 Qualcomm Snapdragon X7 LTE-A
  iSerial                 3 LF71238355031020
  bNumConfigurations      1
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength       0x005f
    bNumInterfaces          2
    bConfigurationValue     1
    iConfiguration          0 
    bmAttributes         0xa0
      (Bus Powered)
      Remote Wakeup
    MaxPower              500mA
    Interface Association:
      bLength                 8
      bDescriptorType        11
      bFirstInterface        12
      bInterfaceCount         2
      bFunctionClass          2 Communications
      bFunctionSubClass      14 
      bFunctionProtocol       0 
      iFunction               0 
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber       12
      bAlternateSetting       0
      bNumEndpoints           1
      bInterfaceClass         2 Communications
      bInterfaceSubClass     14 
      bInterfaceProtocol      0 
      iInterface              0 
      CDC Header:
        bcdCDC               1.10
      CDC Union:
        bMasterInterface        12
        bSlaveInterface         13 
      CDC MBIM:
        bcdMBIMVersion       1.00
        wMaxControlMessage   4096
        bNumberFilters       32
        bMaxFilterSize       128
        wMaxSegmentSize      2048
        bmNetworkCapabilities 0x20
          8-byte ntb input size
      CDC MBIM Extended:
        bcdMBIMExtendedVersion           1.00
        bMaxOutstandingCommandMessages     64
        wMTU                             1500
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x82  EP 2 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0040  1x 64 bytes
        bInterval               9
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber       13
      bAlternateSetting       0
      bNumEndpoints           0
      bInterfaceClass        10 CDC Data
      bInterfaceSubClass      0 
      bInterfaceProtocol      2 
      iInterface              0 
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber       13
      bAlternateSetting       1
      bNumEndpoints           2
      bInterfaceClass        10 CDC Data
      bInterfaceSubClass      0 
      bInterfaceProtocol      2 
      iInterface              0 
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x81  EP 1 IN
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0200  1x 512 bytes
        bInterval               0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x01  EP 1 OUT
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0200  1x 512 bytes
        bInterval               0
Device Qualifier (for other device speed):
  bLength                10
  bDescriptorType         6
  bcdUSB               2.00
  bDeviceClass            0 
  bDeviceSubClass         0 
  bDeviceProtocol         0 
  bMaxPacketSize0        64
  bNumConfigurations      1
Device Status:     0x0000
  (Bus Powered)

I will also see if I can do something with the thread you guys mentioned, but would be really grateful for any further assistance.

Edit: Looks like the solution above fixes ModemManager crashes. I am not sure that my “no Sim” problem is related, but would certainly like to try. Can I just use that repo? Is it easy to roll back to official packages eventually?

Do you have the Mobile Network listed in Gnome-Settings? Should be listed between WiFi, Bluetooth, and Network in settings? If you do, then ModemManager may not be the cause of the ‘No SIM’

Yes it is listed in gnome settings. I agree that ModemManager may not be the problem. Unfortunately, I still don’t know what to do - as I said, the hardware works fine with other operating systems. That should mean that there’s some kind of software/driver problem, right?

I had a similar issue. Worked fine in Windows and Ubuntu. I would suggest filing a bug report over on RedHat Bugzilla.

https://bugzilla.redhat.com/enter_bug.cgi

Also try Reddit Fedora community.

Hey James and @computersavvy ,

so I solved my no-sim problem. I hat noticed that the sim was not detected in Ubuntu anymore, either. So I tripple checked the actual sim slot for any damage, but eventually decided to see if it still worked using windows. There, I installed the EM7455 driver from Lenovo’s site. The WWAN modem immediately worked and a connection was established.

After that, the WWAN card started working in Fedora, too. I can only assume that there was something “stuck” in a wrong state in the card’s firmware which got fixed by the windows driver.

So now I’m stuck with the same problem which James was talking about, which apparently can indeed be fixed by the newer ModemManager version, which I’ll try to build and install next. It is really frustrating that the package’s maintainer apparently isn’t reacting to bump requests. I hope that this is not a common theme with Fedora?

A bug report is the best way to get the attention of responsible parties. It is available for open review by all and most get resolved fairly quickly.

There is no need to build ModemManager. There are four packages needed. Already built. If you are using Fedora Silverblue you will need to override the existing packages. Then revert them back before accepting the new packages when they are finally available. It has been several months and still no upgrade to the packages needed uploaded to the repository.