Hi Michel, On 7/16/20, Michel Macena Oliveira <michel@xxxxxxxxxxxxxxxxxxxx> wrote: > Hi, sorry for my newbie question, > What is the status of the serial port driver? > I've written some code to use serial ports for the generic kernel linux, > And now I want to write something similar for the real time kernel, do > I have to use some specific library, flags or something or is it just > the same settings? > > I'm asking because now I need to take into account the serial access > in the scheduler to ensure a real time behavior . > > Any help, advice, hint or tips would be appreciated. > Do you mean that you wrote some code that works with a /dev/tty* serial port? In some kernel versions (e.g 4.19) we saw high latencies in the rx path of serial drivers. I think that this is due to rx handled in the context of a workqueue which also handles other system activities. We found a workaround to this problem. If I remember correctly we create a dedicated thread for the port and assign it a high priority. Itai Handler
