Mwifiex driver crashing when using AP and station mode

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Hello! Thank you for providing a detailed description and relevant logs. Based on your report and current documentation, here’s a summary and some recommendations:

Key Points

  1. AW-CM276NF Module Limitation
    The Wi-Fi module on your Verdin iMX8M Plus (AW-CM276NF) is a single MAC device, which means it can only operate on one channel at a time—across both AP (uap0) and STA (mlan0) modes. Running concurrent AP and station interfaces can therefore result in conflicts if the underlying driver/firmware isn’t handling these transitions robustly (reference).

  2. Driver and Firmware Issues
    The mwifiex_sdio driver is known to have stability issues, particularly when toggling between AP and STA roles or manipulating both interfaces concurrently, and especially on newer kernel versions. Your logs indicate the firmware is entering a bad state after these operations, which matches known limitations (reference). The line PREP_CMD: FW is in bad state and other timeouts suggest kernel/driver/firmware desynchronization.

  3. Recent SDIO Driver Concerns
    Investigations point to driver issues most pronounced when using the SDIO-based Wi-Fi on Verdin iMX8M Plus modules (reference).

Recommendations

1. Channel & Band Consistency

Even though you noted that the crash seems independent of the Wi-Fi band/channel, the documentation still recommends for dual mode (AP + STA) on single-MAC devices, both interfaces should use the same band and channel. Mismatched settings often escalate driver/firmware instability.

  • Ensure both the AP (hostapd) and station (mlan0) are on the same band and, ideally, the same channel. If possible, configure both networks to operate in 5GHz band on, for example, channel 36.

2. Driver Alternatives

If you experience instability with the mainline mwifiex_sdio driver, it is possible to explore NXP’s downstream kernel drivers, which may offer more robust support for this use case (reference). However, migrating to these drivers may involve custom kernel development.

3. Reset & Recovery Script

When the Wi-Fi crashes and interfaces disappear, a hardware-level reset or module reload is required. Consider automating this with a script to unbind/rebind the SDIO device, or perform a system reboot upon detection of failure. While this is more of a workaround, it can restore network functionality in unattended systems.

4. Minimize State Flipping

Reduce the frequency of state changes between AP and STA, and avoid frequent toggling or rapid connect/disconnect cycles since the current driver/firmware combination seems especially fragile under these conditions.

5. Monitor for Updates

Stay updated with new Torizon OS releases, as ongoing work may produce fixes or workarounds for your hardware/kernel combination.

Important:
Due to the module and driver limitations, fully robust AP+STA operation is not always achievable on this platform. Review your application requirements and, if possible, consider separating infrastructure (STA) and soft-AP features across different hardware modules to maximize stability.

Let me know if you’d like configuration examples or additional troubleshooting steps.

Best regards,
Toradex AI Assistant.