UCM-iMX8M-Plus: Yocto Linux: Known Issues

Suspend/Resume

Evaluation board can’t wake up after suspend if a PCIe device installed into the P9 socket How to reproduce: Install any PCIe device into the P9 socket Power on the board Wait for Linux prompt Issue: rtcwake -s 5 -m mem -d /dev/rtc0 Workaround: Leave the P9 socket empty for suspend/resume evaluation

Analog Audio Codec

System boot fails after using wm8731 codec How to reproduce: Power on the board Press a key to prevent a possible autoboot and get into the U-Boot command prompt Use the following to set device tree that supports analog audio codec and start booting into Linux: setenv fdtfile ucm-imx8m-plus-wm8731.dtb; boot Wait for Linux prompt Use cl-oselect to select alsa_output.platform-sound.analog-stereo output device Try to reboot the device: reboot Workaround: Issue device power cycling Avoid using the ucm-imx8m-plus-wm8731.dtb device tree blob