I have code that puts my device to VLPS when the SLEEP bit is set (due to a suspend) on the USB bus. I'm using the Freescale USB Stack v4.1.1. I monitor USB_USBTRC0_USBRESMEN_MASK to see if I can enter VLPS and then I do.
This works in most cases, but I'm finding on some platforms with some corner cases it does not. I've more or less
proven that I get stuck in the VLPS state instead of asynchronously resuming.
When I get stuck I'm seeing that my Clear Feature Remote Wakeup is getting Stalled as Well.
Is there any known issues with this or known limitations with certain systems?
Is there a suggested approach for power management with the USB stack?