On Sat, May 28, 2022 at 2:22 AM Mychaela N. Falconia <falcon@xxxxxxxxxxxxxxx> wrote: > > Add a manual_rtsdtr sysfs attribute to suppress automatic raising of > DTR and RTS modem control signals on serial port open. > > This special mode can be used to prevent undesirable side effects on > open for applications where these lines are used for non-standard > purposes such as generating power-on and reset pulses. As I read this I think of the pins used as GPIOs. So, sounds like what we need instead is to list the pins that are used for (dedicated) GPIOs and pass this information to serial mctrl layer and perhaps prepare that layer to handle exclusions like these. The given (in this series) approach sounds to me like a (hackish?) workaround of this simple idea. -- With Best Regards, Andy Shevchenko