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. -- Jon H. LaBadie jcu at labadie.us