change parity on the fly? about serial

[tarm]

I have a similar problem with a bootloader.

I don't think it would be right to change the baud rate while a read operation is occurring. That would cause a race condition and you would not know whether the data returned from the read was before or after the baud rate change (some bytes at different baud rates look valid at other baud rates depending on how the hardware samples the values). You should finish the read before changing the baud rate.

As you mentioned in the UPDATE, one way to force the read to finish and get a point to synchronize the code between goroutines is to use a read timeout. That is what I recommend and what I do for my bootloader 9600->faster transition.

I'm not sure what you mean by "EOF due to a port disconnect". As far as I know most serial hardware does not provide a way to determine a port disconnect. Unless you mean the whole module disappears (ie a USB<->serial cable gets unplugged at the USB side.

[jcw]

"EOF due to a port disconnect"

Yes, I meant an unplugged cable. It'd be useful to detect the difference between an unplugged cable (and possibly try to re-open the device periodically), and a timed-out read request.

Changing parameters mid-flight is not necessarily a problem: the upload process starts with a sync handshake, ignoring any characters left over from a previous session until they're in sync.

[jcw]

I'll close this issue. Feel free to re-open of course if you want to keep it around.
I've switched to go.bug.st/serial.v1, which supports on-the-fly mode changes.
Thanks for your response.