Benjamin Ogles

## Issue Description ## Attempting to transmit from an X300 with a UBX160 daughter board at 200MSPS results in frequent under runs when using UHD version 4.0 or 4.1. I...

CHDR control endpoint consumes a CPU core polling a socket with no timeout

1

## Issue Description ## The X300 uses a thread owned by the `chdr_ctrl_endpoint` class to poll for control ACKs and asynchronous command responses. https://github.com/EttusResearch/uhd/blob/748162e6a9a018f6cf377be8f9a68a7445060336/host/lib/rfnoc/chdr_ctrl_endpoint.cpp#L121 Calls to receive UDP packets eventually...