How do I kill the shell session on ttyS0? ls did nothing. nor stty sane but I think I saw all those characters echoed back. On 12/14/23 00:04, Jon LaBadie wrote: > On Wed, Dec 13, 2023 at 08:45:31PM -0500, Robert Moskowitz wrote: >> I have Centos 7 arm32 running on a Cubieboard and I am logged in as root >> on its serial uart from another system. >> >> On that system I use >> >> screen /dev/ttyUSB0 115200 >> >> Well it was working well for a couple days, but now only garbage comes >> across. Something messed up the serial link. >> >> pulling the usb cable to the usb/serial adapter does not reset things. >> >> I can ssh into the server and see root logged into ttyS0 >> >> How do I reset that serial port so that I can work on the system? >> >> thanks >> > > Channeling old memories of serial communications :(( > > Sounds like you are still connected. One way to tell is > to pretend things are working even if you only see garbage. > > For example, if you press <Enter> several times, do you > get the same garbage each time (likely the shell prompt > coming back to you). > > If after an Enter and return garbage you type ls<Enter> > is the garbage different, probably larger, and likely > ending with the same garbage as a solo <Enter> (the prompt) > > Then try to reset your stty communication settings by > carefully typing > > stty sane<Enter> > > Don't try to correct typo's, just hit enter and start again. > > Should that not work, ssh back in and kill the shell session > on ttyS0. Typically the communication settings are returned > to a default set by a program called getty which then exec's > into the login program. > > Good luck. >