MC7421 and EM7565 stuck in weird mode

[nicholas.leong]

Hi all,

We are using 2 variants of the Sierra Wireless modem (MC7421 and EM7565) in the field on an edge device. We have about 300+ devices now but recently we are experiencing devices losing 4G connectivity completely. Note we did not attempt any firmware upgrade or reconfiguration via QMI or AT command, just using ModemManager and NetworkManager with DBus to setup the GSM connection. The modem is connected to a M.2 connector.

After getting the device back, we noticed that the modem was not being recognized as a QMI device; hence, ModemManager could not detect and configure it.

Taking the MC7421 device as an example, we expect the device vendor and product ID to be 1199:9091, but it is now showing up as 1199:9090. However, only a single USB interface shows up ‘/dev/ttyUSB0’, but it does not respond to any AT command.

We also tried using usb_modeswitch to force it to 9091 with the command below but had no luck.

usb_modeswitch -v 1199 -p 9090 -V1199 -P 9091 -S

We also tried to reset the device via usb_modeswitch and that did not do anything as well.

usb_modeswitch -v 1199 -p 9090 -R

Below is the output of dmesg when forcing a reboot

[Wed Feb  5 23:55:34 2025] qcserial ttyUSB0: Qualcomm USB modem converter now disconnected from ttyUSB0
[Wed Feb  5 23:55:34 2025] qcserial 1-2:1.0: device disconnected
[Wed Feb  5 23:55:35 2025] usb 1-2: USB disconnect, device number 8
[Wed Feb  5 23:55:36 2025] usb 1-2: new high-speed USB device number 9 using tegra-xusb
[Wed Feb  5 23:55:36 2025] usb 1-2: New USB device found, idVendor=1199, idProduct=9090
[Wed Feb  5 23:55:36 2025] usb 1-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[Wed Feb  5 23:55:36 2025] usb 1-2: Product: Sierra Wireless MC7421 Qualcomm\xc3\x82\xc2\xae Snapdragon\xc3\xa2\xc2\x84\xc2\xa2 X16 LTE-A
[Wed Feb  5 23:55:36 2025] usb 1-2: Manufacturer: Sierra Wireless, Incorporated
[Wed Feb  5 23:55:36 2025] usb 1-2: SerialNumber: 912075235301B114
[Wed Feb  5 23:55:36 2025] qcserial 1-2:1.0: Qualcomm USB modem converter detected
[Wed Feb  5 23:55:36 2025] usb 1-2: Qualcomm USB modem converter now attached to ttyUSB0

Here’s the output of lsusb -v -d 1199:9090

root@7705d12:~# lsusb -v -d 1199:9090 

Bus 001 Device 009: ID 1199:9090 Sierra Wireless, Inc. 
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               2.10
  bDeviceClass            0 (Defined at Interface level)
  bDeviceSubClass         0 
  bDeviceProtocol         0 
  bMaxPacketSize0        64
  idVendor           0x1199 Sierra Wireless, Inc.
  idProduct          0x9090 
  bcdDevice            0.00
  iManufacturer           1 Sierra Wireless, Incorporated
  iProduct                2 Sierra Wireless MC7421 Qualcomm® Snapdragonâ
                                                                         ¢ X16 LTE-A
  iSerial                 3 912075235301B114
  bNumConfigurations      1
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength           32
    bNumInterfaces          1
    bConfigurationValue     1
    iConfiguration          0 
    bmAttributes         0xa0
      (Bus Powered)
      Remote Wakeup
    MaxPower                2mA
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           2
      bInterfaceClass       255 Vendor Specific Class
      bInterfaceSubClass    255 Vendor Specific Subclass
      bInterfaceProtocol    255 Vendor Specific Protocol
      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
Binary Object Store Descriptor:
  bLength                 5
  bDescriptorType        15
  wTotalLength           22
  bNumDeviceCaps          2
  SuperSpeed USB Device Capability:
    bLength                10
    bDescriptorType        16
    bDevCapabilityType      3
    bmAttributes         0x00
    wSpeedsSupported   0x000e
      Device can operate at Full Speed (12Mbps)
      Device can operate at High Speed (480Mbps)
      Device can operate at SuperSpeed (5Gbps)
    bFunctionalitySupport   1
      Lowest fully-functional device speed is Full Speed (12Mbps)
    bU1DevExitLat          10 micro seconds
    bU2DevExitLat        2047 micro seconds
  USB 2.0 Extension Device Capability:
    bLength                 7
    bDescriptorType        16
    bDevCapabilityType      2
    bmAttributes   0x00000002
      Link Power Management (LPM) Supported
Device Status:     0x0000
  (Bus Powered)

Any idea what’s happening with the Modem?

[jyijyi]

it was kept in download mode
you can try to download FW and see if you can recover it

[nicholas.leong]

Thanks for the quick reply.

What’s download mode? I’m looking at the product’s technical specification but it doesn’t mention anything about a download mode.

Does this indicate that there’s something wrong with the firmware on the modem? Can you point to the a guide/ docs on how I can download the FW and recover it?

[jyijyi]

it means boot-and-hold mode in specification

See if this helps to download FW:

Unable to upgrade firmware for EM7411

@leo You might also want to check what rights you have against that interface, you might be able to see it but not write to it. pi@raspberrypi:~ $ ls /dev autofs cuse i2c-1 loop5 mmcblk0p2 ram11 ram7 shm tty12 tty21 tty30 tty4 tty49 tty58 ttyAMA0 vcs1 vcsa3 vcsu3 video14 block disk initctl loop6 mqueue ram12 ram8 snd tty13 tty22 tty31 tty40 tty5 tty59 ttyprintk vcs2 vcsa4 vcsu4 video…

You can download the tool here:
https://source.sierrawireless.com/resources/airprime/software/mbpl/mbpl-software-latest/#sthash.ZXRwiiKx.dpbs

[nicholas.leong]

I haven’t attempted the firmware update, however it seems like it requires both /dev/ttyUSB0 and /dev/cdc-wdm0.

On my affected modems, only ttyUSB0 exist and cdc-wdm0 does not. Can I still update the firmware?

[jyijyi]

i think so, you can try

Swiflash PORT not found

If you are using fwdwl application in boot and hold mode, you need to add “-c QMI” parameter: owner@ubuntu:~/QMI/MBPL/MBPL_SDK_R32_ENG2-fwdwl.bin/SampleApps/lite-fw-download$ sudo ./bin/fwdwl-litehostx86_64 -c QMI -m 4 -d /dev/ttyUSB0 -f /home/owner/Desktop/FW_WP76/ Application version: 1.0.2303.0 INFO: QDL Port: /dev/ttyUSB0 INFO: Device Path: INFO: FW Path: /home/owner/Desktop/FW_WP76/ Modem is already in QDL mode. Continuing FW download. Waiting for modem to come up in BOOT and HOLD mode…

[nicholas.leong]

I’m trying to flash the same firmware version used by the rest of our fleet. The MC7421 uses the firmware version shown below.

Where can I download the older release? I can’t seems to find an older build from this link: https://source.sierrawireless.com/resources/airprime/minicard/74xx/em_mc74x1-approved-fw-packages/

firmware revision: SWI9X50C_01.14.03.00 b06bd3 jenkins 2020/09/23 10:53:35
carrier config: default

[jyijyi]

you can see here:

Where to find old EM7565 firmware?

Where to find old EM7565 firmware? Now i’m using fw 01.14.02.00 version, but i want to try some old generic versions, where i can find them? Thanks for answer

[nicholas.leong]

so I tried to flash the MC7421 modem with the command below and it returned an error code FW download failed: eSDP_FWDWL_ERR_FIREHOSE_STATE_ERR(120)

./fw-download-toolarm -c QMI -d /dev/ttyUSB0 -f /mnt/data/sw_firm/

Subsequent command to flash the firmware fails and recommended a power cycle of the modem, which I attempted via usb_modeswitch.

When the modem powers on again, it’s not being registered and dmesg shows its failing to enumerate the USB device

[Thu Feb  6 04:28:33 2025] qcserial ttyUSB0: Qualcomm USB modem converter now disconnected from ttyUSB0
[Thu Feb  6 04:28:33 2025] qcserial 1-2:1.0: device disconnected
[Thu Feb  6 04:28:33 2025] usb 1-2: reset high-speed USB device number 4 using tegra-xusb
[Thu Feb  6 04:28:34 2025] usb 1-2: Device not responding to setup address.
[Thu Feb  6 04:28:36 2025] usb 1-2: Device not responding to setup address.
[Thu Feb  6 04:28:36 2025] usb 1-2: device not accepting address 4, error -71
[Thu Feb  6 04:28:36 2025] usb 1-2: reset high-speed USB device number 4 using tegra-xusb
[Thu Feb  6 04:28:37 2025] usb 1-2: Device not responding to setup address.
[Thu Feb  6 04:28:37 2025] usb 1-2: Device not responding to setup address.
[Thu Feb  6 04:28:37 2025] usb 1-2: device not accepting address 4, error -71
[Thu Feb  6 04:28:37 2025] usb 1-2: reset high-speed USB device number 4 using tegra-xusb
[Thu Feb  6 04:28:38 2025] usb 1-2: device descriptor read/64, error -71
[Thu Feb  6 04:28:38 2025] usb 1-2: device descriptor read/64, error -71
[Thu Feb  6 04:28:38 2025] usb 1-2: reset high-speed USB device number 4 using tegra-xusb
[Thu Feb  6 04:28:38 2025] usb 1-2: device descriptor read/64, error -71
[Thu Feb  6 04:28:38 2025] usb 1-2: device descriptor read/64, error -71
[Thu Feb  6 04:28:39 2025] usb 1-2: USB disconnect, device number 4
[Thu Feb  6 04:28:39 2025] usb 1-2: new high-speed USB device number 5 using tegra-xusb
[Thu Feb  6 04:28:39 2025] usb 1-2: Device not responding to setup address.
[Thu Feb  6 04:28:39 2025] usb 1-2: Device not responding to setup address.
[Thu Feb  6 04:28:39 2025] usb 1-2: device not accepting address 5, error -71
[Thu Feb  6 04:28:39 2025] usb 1-2: new high-speed USB device number 6 using tegra-xusb
[Thu Feb  6 04:28:39 2025] usb 1-2: Device not responding to setup address.
[Thu Feb  6 04:28:39 2025] usb 1-2: Device not responding to setup address.
[Thu Feb  6 04:28:40 2025] usb 1-2: device not accepting address 6, error -71
[Thu Feb  6 04:28:40 2025] usb usb1-port2: attempt power cycle
[Thu Feb  6 04:28:41 2025] usb 1-2: new high-speed USB device number 7 using tegra-xusb
[Thu Feb  6 04:28:41 2025] usb 1-2: device descriptor read/64, error -71
[Thu Feb  6 04:28:41 2025] usb 1-2: device descriptor read/64, error -71
[Thu Feb  6 04:28:42 2025] usb 1-2: new high-speed USB device number 8 using tegra-xusb
[Thu Feb  6 04:28:42 2025] usb 1-2: device descriptor read/64, error -71
[Thu Feb  6 04:28:42 2025] usb 1-2: device descriptor read/64, error -71
[Thu Feb  6 04:28:42 2025] usb usb1-port2: unable to enumerate USB device

[nicholas.leong]

Nvm, after doing a hard reboot of the entire system, the modem is now showing up and in QMI mode!

[nicholas.leong]

@jyijyi thanks for the help.

It was weird that the fw download tools says that the firmware update failed, yet the modem works when we power cycle the entire device. We’ll test on another modem we have that’s experiencing the same issue and see if we can repeat the process and update its firmware.

Do you have any idea what could cause the modem to get stuck in the boot-and-hold mode in the first place? Does this indicate that the firmware was corrupted in the field?

[jyijyi]

i remember there is chance to corrupt the module if not following the power down sequence in specification