OS:linux 2.4.26

sometimes, possible after noise in line, I receive situation when
select() on port return then there are data available for read but
following read() return 0 bytes.

according to man tcsetattr and analogue with socket I understand this
situation as EOF.

All following pair select()/read() return same situation regardless
from data in port.

serial port open/tune via code:

<code>
port->fd =3D open(devfile, O_RDWR | O_NOCTTY);

if (port->fd =3D=3D -1) {syslog(LOG_ERR,"watcher_open_port():error
opening '%s': %m", devfile); free(port);return NULL; }


if (tcgetattr(port->fd, &ti) < 0)

{ syslog(LOG_ERR, "%s(%s):error getting terminal line modes:
%m",__func__, devfile); close(port->fd);free(port); return
NULL; }



cfmakeraw(&ti);

cfsetispeed(&ti, WATCHER_PORT_SPEED);

cfsetospeed(&ti, WATCHER_PORT_SPEED);



//c_iflag &=3D
 ~(IGNBRK|BRKINT|PARMRK|ISTRIP|INLCR|IGNC
R|ICRNL|IXON);

ti.c_iflag |=3D IGNBRK;//??? =D0=B2=D0=BE=D0=B7=D0=BC=D0=BE=D0=B6=D0=
BD=
=D0=BE =D0=B8=D0=BC=D0=B5=D0=B5=D1=82 =D1=81=D0=BC=D1=8B=D1=81=D0=BB
 =D0=BE=D1=81=D1=82=D0=B0=D0=B2=D0=B8=D1=
82=D1=8C =D1=8D=D1=82=D0=BE=D1=82 =
=D1=84=D0=BB=D0=B0=D0=B3 =D1=81=D0=BD=D1=8F=D1=82=D1=8B=D0=BC =D0=B0 =D0=B2=
=D0=BC=D0=B5=D1=81=D1=82=D0=BE
=D0=BD=D0=B5=D0=B3=D0=BE  =D0=BF=D0=BE=D0=B4=D0=BD=D1=8F=D1=82=D1=
8C BRKINT?=
??
ti.c_iflag |=3D IGNPAR;//Ignore framing errors and parity errors.

ti.c_iflag &=3D ~(INPCK | PARMRK);

ti.c_iflag &=3D ~(IXOFF | IXON | IXANY);    /* disable start/stop i/o
flow control*/


//c_oflag &=3D ~OPOST;



ti.c_cflag &=3D ~(PARENB | PARODD);  /* no parity */

ti.c_cflag &=3D ~CSTOPB;             /* 1 stop bit */

ti.c_cflag &=3D ~CRTSCTS;            /* no i/o rts/cts flow control
*/
ti.c_cflag |=3D CLOCAL;

ti.c_cflag |=3D HUPCL;

ti.c_cflag |=3D CREAD;



//c_lflag &=3D ~(ECHO|ECHONL|ICANON|ISIG|IEXTEN);

//Disable  flushing  the  input and output queues when
generating the SIGINT, SIGQUIT and SIGSUSP signals.
//ti.c_lflag &=3D ~(NOFLSH);//???=D0=B2=D0=BE=D0=B7=D0=BC=D0=BE=D0=
=B6=D0=BD=D0=BE
 =D0=BF=D0=BE=D1=82=D1=80=D0=B5=D0=B1=D1=
83=D0=B5=D1=82=D1=81=D1=8F =D1=83=
 =D1=81=D1=82=D0=B0=D0=BD=D0=BE=D0=B2=D0=
B8=D1=82=D1=8C/=D1=81=D0=BD=D1=8F=
=D1=82=D1=8C???



ti.c_cc[VMIN] =3D 0;

ti.c_cc[VTIME] =3D 0;



if (tcsetattr(port->fd, TCSANOW, &ti) < 0)

{ syslog(LOG_ERR,"%s(%s):error setting terminal line modes: %m",
__func__,  devfile); close(port->fd);free(port); return
NULL; }
</code>

any idea???

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