solved, was Re: serial on neopi neo

[Ian Lepore]

On Fri, 2018-02-09 at 12:28 +0200, Daniel Braniss wrote:
> 
> > 
> > On 9 Feb 2018, at 12:02, Daniel Braniss <danny at cs.huji.ac.il>
> > wrote:
> > 
> > 
> > 
> > > 
> > > On 8 Feb 2018, at 17:30, Daniel Braniss <danny at cs.huji.ac.il>
> > > wrote:
> > > 
> > > hi,
> > > after fiddling with the dts file (with the help from Milo), I got
> > > 2 serial ports to work(apart from the /dev/ttyu0),
> > > but not together! ie, if i try each one individually all is ok,
> > > but once I open both of them, only
> > > /dev/ttyu1 works, /dev/ttyu2 hangs (i have yet to see if its the
> > > output or input)
> > > 
> > > any ideas?
> > I have!
> > 
> > I’m using the ‘what i thought’ unused pins (CTS/RTS) to drive some
> > leds!
> > 
> > I do set, via tcsetattr(3) to ignore these (ie no modem, no flow
> > control) but it seems the driver is ignoring this.
> > how can I tell the serial/uart to ignore them?
> was sent out too early!
> 
> doing a cfmakeraw(3) is what screwed me up!
> now all is ok!

That's strange, because I was about to reply to the prior mail
suggesting you start with a cfmakeraw() before tcsetattr().  I always
start with makeraw then set just the things I want, like:

    tcgetattr(fd, &t);
    cfmakeraw(&t);
    t.c_iflag &= ~(IXON | IXOFF | IXANY);
    t.c_cflag &= ~(PARENB | CSTOPB | CSIZE | CRTSCTS);
    t.c_cflag |= CLOCAL | CREAD | CS8;
    cfsetspeed(&t, whatever);
    tcwriteattr(fd, TCSANOW, &t);

-- Ian