Hi Adam, On Mon, Sep 10, 2018 at 3:10 PM, Adam Rudziński <adam.rudzinski@xxxxxxxxxx> wrote: > Hello Fabio, > > I was trying to use 4.12.4 and 4.14.39. There have been many imx rs485 related changes lately, so I would recommend you to try 4.19-rc3. > The failure is that when Linux disables the UART peripheral, control over > CTS_B is lost and it defaults to high voltage state. That makes sense for > eg. RS232, but not for using this signal as positive logic "driver enable", > which should default to low voltage state. > > I had a look at how it is done in the latest kernels, I think it's the same > thing in principle. > > I am going to fix this, just I would like to find out which of the suggested > solutions is better suited for Linux. Personally, I opt for solution 1 - > keep UART enabled all the time - but maybe there is a good reason not to do > that. Maybe you could submit a RFC patch for discussion. Thanks
