machine.lightsleep wake on uart

[CrabbyPete]

I am using the machine.lightsleep and it works great. I am using it to connect to a Quectel BC66 modem, which I can also put in PSM mode. The one problem I have is if the modem wakes up and sends a message on the UART, and if the Pico is in machine.lightsleep, it never wakes up to see that a message was sent. I can wake it up on an interrupt, but can I wake it up when the modem sends a command?

Here is the current code.
https://github.com/CrabbyPete/watchible/blob/master/software/main.py