Wi-Fi reconnection issue on Verdin iMX8M Plus (Dahlia)

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Wi-Fi Connection Issues on Verdin iMX8M Plus

Based on your description of Wi-Fi disconnection issues that require power cycling to resolve, this appears to be related to the Wi-Fi module driver behavior. The Verdin iMX8M Plus uses the Azurewave AW-CM276NF Wi-Fi module based on the NXP 88W8997 chipset (1).

Known Driver Limitations

The documentation indicates that there are some use case limitations with the mainline driver used in BSP releases (1). Specifically:

  • Some use cases don’t work with the mainline Marvell WiFi-Ex driver included in BSP 5 and later versions (1)
  • The driver included is the Marvell WiFi-Ex driver from Mainline Linux kernel along with its corresponding firmware (1)
  • Downstream NXP drivers have been tested and seem to work well for some use cases that are not supported by the mainline driver (1)

Potential Hardware-Related Considerations

Your observation about power cycling being necessary suggests a potential hardware state issue. The Verdin iMX8M Mini Errata documents a related issue where Wi-Fi module power rails cannot be turned off properly (2). While this specific errata is for the Mini variant, similar power management issues could affect the Plus variant.

The errata states that after booting, you should turn on the power rails for the Wi-Fi and Bluetooth module only if the radio is required and keep the rails turned on or reboot the system if the rails need to be turned off again (2).

Recommended Troubleshooting Steps

  1. Check driver logs during disconnection events using dmesg to identify specific error patterns
  2. Monitor Wi-Fi module power state during software reboots vs. power cycles
  3. Consider testing with downstream NXP drivers if the mainline driver continues to exhibit issues (1)

Additional Context

Community reports show similar Wi-Fi subsystem issues where the mwifiex_sdio driver can experience command timeout errors and bridge packet limit issues, particularly under heavy network load scenarios (3).

Since you’re using a custom Yocto build with BSP 7.2.0, the issue appears to be related to the driver’s ability to properly reinitialize the Wi-Fi hardware state during software reboot compared to a full power cycle reset.

Best regards, Toradex AI Assistant.