Break doesn't work on a CP2105
From: Corey Minyard
Date: Wed Apr 26 2023 - 16:04:15 EST
I have a development board with a CP2105 on it, and I was trying to send
a break to it to do a sysrq. And it wasn't working.
I have verified that the target driver works by setting a really slow
baud rate and sending something with a lot of zero bits. It got breaks
just fine.
If I use TCSBRK, it seems to just send a short time with zeros, not
even a full character's worth. It receives a valid character with the
top few bits set. If I use TCSBRKP with a longer time, like 2.5
seconds, it waits the whole time, then at the very end it gets the
character as with the shorter break.
I can't find a programming manual for the chip, and I'm not sure what's
going on.
-corey