Baofeng shipped me an ostensibly pl2303-based programming cable with my UV-82, which I successfully used to program my radio with CHIRP on Ubuntu about two years ago.
Today, I am now on Ubuntu 16.04, and I couldn't get CHIRP to talk to the same radio over the same cable. It turns out that newer Ubntu versions ship a driver for the pl2303 that holds DTR low on the serial side (at least until the port is opened), and this puts the radio into transmit mode. The radio needs a little time to come out of it before it can talk to CHIRP, but CHIRP forges ahead with its commands as soon as it opens the port.
It's not crazy behavior on the part of the Ubuntu driver; DTR high means the computer is ready to talk to the device, and if the port is closed the computer is probably not ready to talk to the device. So I think it's appropriate to patch CHIRP rather than try and change the behavior on the LInux side.
This patch explicitly sets DTR high, and waits a bit, before trying to talk to the radio. I'm patching the UV5R driver, which gets used for the UV-82. This fixes issue #4165, which I reported so I could send in this patch. I have successfully used this patch to program my radio with CHIRP.
If there are any other radios that misbehave when DTR is low, and any other cables in common use based on this chip, it may make sense to patch those radio drivers as well.