On page 9 of the monitor's manual (URL: ftp://ftp.dell.com/Manuals/all-products/esuprt_display_projector/esuprt_Display/dell-u2312h_User%27s%20Guide_en-us.pdf ), is it really necessary for me to connect the USB upstream port to my PC?
Additionally could someone suggest to me, with examples, what USB devices I can use on the 4 USB downstream ports (two at the bottom of the monitor, two on the side)?
If you want the four monitor USB ports to work, the USB upstream cable must be connected to a USB port on the PC. A USB key or USB HDD. I would not plug essential boot devices like keyboard or mouse into the monitor USB ports.