System freezes - Githubissues

Hi,

I'm getting intermittent system freezes on multiple new Raspi B+ V1.2 boards running Raspian / Linux 3.18.7+ and the actual module driver. SysRq doesn't work; no kernel dump, nothing logged.

Following test code will freeze my Pi in a matter of minutes.

There's nothing connected to the RasPiComm Board.
Code is running fine with an external USB RS485 converter

#include <stdio.h> /* included for printf() */
#include <fcntl.h> /* included for O_RDWR, O_NOCTTY and O_NDELAY */
#include <termios.h> /* included for functions and defines used in set_interface_attribs */
#include <string.h> /* included for memset */
#include <unistd.h>
#include <errno.h>

#define READER "/dev/ttyRPC0"
//#define READER "/dev/ttyUSB0"
int comport;
unsigned char mesg1[]= {0x01,0x02,0x03,0x04};

/*
Source:
http://stackoverflow.com/questions/6947413/how-to-open-read-and-write-from-serial-port-in-c
*/
int set_interface_attribs (int fd, int speed, int parity)
{
  struct termios tty;
  memset (&tty, 0, sizeof tty);
  if (tcgetattr (fd, &tty) != 0)
  {
    printf("error using tcgetattr\n");
    return -1;
  }

  cfsetospeed (&tty, speed);
  cfsetispeed (&tty, speed);

  tty.c_cflag = (tty.c_cflag & ~CSIZE) | CS8; // 8-bit chars
  // disable IGNBRK for mismatched speed tests; otherwise receive break
  // as \000 chars
  tty.c_iflag &= ~IGNBRK; // ignore break signal
  tty.c_lflag = 0; // no signaling chars, no echo,
  // no canonical processing
  tty.c_oflag = 0; // no remapping, no delays
  tty.c_cc[VMIN] = 0; // read doesn't block
  tty.c_cc[VTIME] = 5; // 0.5 seconds read timeout

  tty.c_iflag &= ~(IXON | IXOFF | IXANY); // shut off xon/xoff ctrl

  tty.c_cflag |= (CLOCAL | CREAD);// ignore modem controls,
  // enable reading
  tty.c_cflag &= ~(PARENB | PARODD); // shut off parity
  tty.c_cflag |= parity;
  tty.c_cflag &= ~CSTOPB;
  tty.c_cflag &= ~CRTSCTS;

  if (tcsetattr (fd, TCSANOW, &tty) != 0)
  {
    printf("error from tcsetattr\n");
    return -1;
  }
  return 0;
}

int main(int argc, char** argv)
{
  fprintf(stdout,"Test for RasPiComm\n");

  fprintf(stdout,"Open Port %s...\n", READER);
  if ( (comport = open(READER, O_RDWR | O_NOCTTY | O_NDELAY)) < 0 )
  {
    fprintf(stdout,"failed.\n");
    fprintf(stdout,"possible causes:\n");
    fprintf(stdout,"1) the raspicomm device driver is not loaded. type 'lsmod' and verify that you 'raspicommrs485' is loaded.\n");
    fprintf(stdout,"2) the raspicomm device driver is in use. Is another application using the device driver?\n" );
    fprintf(stdout,"3) something went wrong when loading the device driver. type 'dmesg' and check the kernel messages\n");
    return -1;
  }
  printf("successful. fd=%i\n", comport);
  // configure the port
  if (set_interface_attribs(comport, B19200, PARENB) < 0)
  {
    fprintf(stdout,"Error configuring RS485 Port.\n");
    return -2;
  }
    int count=0;
  while(1)
  {
    fprintf(stdout,"Sending String \n");
    int written=write(comport,mesg1,4);
    if(written<4)
    {
            fprintf(stdout,"Write ERROR!");
    }
    if(count%20==0)
    {
        fprintf(stdout,"\nKLICK\n");
        count=0;
        }
        count++;

    usleep(10000);
  }
  //Never reached
  close(comport);
}

amescon / raspicomm-module

System freezes #8