I'm currently experiencing an issue on a board very similar to the i.MX28 dev board, running the 2.6.35_10.12.01 Linux kernel. What is happening is that after an extended period of standby sleep (so far longer than a half-hour), on occasion the system will resume running extremely slowly and unresponsively. This continues until the system is put back into standby and re-awakened. I was able to determine that the process listed as "[usb_wakeup thre]" was consuming 93% - 98% of CPU cycles and never stops this level of CPU usage. Nothing is plugged into either of the USB ports. The USB's are not set as wake-up sources and in fact the system does not wake up on insertion of flash drives or a host.
Has anyone experienced this issue on the i.MX28? Thanks in advance for any help or advice.