serielle schnittstelle: abfragen von CTS in thread

kistbier

hallo,

ich habe ein programm mit posix-threads geschrieben in dem ich unter anderem ein display an der seriellen schnittstelle ansteuere. daten kann ich aber nur senden wenn CTS=1 ist.

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

# include <stdio.h>
# include <unistd.h>
# include <fcntl.h>
# include <sys/ioctl.h>
# include <linux/serial.h>
# include <linux/serial_reg.h>

# if defined __GLIBC__
#   include <sys/io.h>
# else
#   include <asm/io.h>
# endif

#include "define.h"
#include "conf.h"
#include "log.h"

static int eakit_cts_fd  = -1;
static int eakit_cts_adr = 0;

int eakit_cts_init_flag   = FALSE;
int eakit_cts_deinit_flag = FALSE;
int eakit_cts_ready       = FALSE;

/**
 * init
 *
 */
int eakit_cts_init(void)
{
	struct serial_struct serial_port;

	log_printf(LOG_DEBUG, "eakit_cts_init(): initializing\n");

	if ((eakit_cts_fd = open(config_getstr(EAKIT_DEVICE_STR, EAKIT_DEVICE), O_RDONLY)) == -1)  {
		log_printf(LOG_ERROR, "eakit_cts_init(): unable to open device '%s'\n", config_getstr(EAKIT_DEVICE_STR, EAKIT_DEVICE));

		return FALSE;
	}

	if (ioctl(eakit_cts_fd, TIOCGSERIAL, &serial_port) == -1) {
		log_printf(LOG_ERROR, "eakit_cts_init(): ioctl() failed\n");

		return FALSE;
	}

	eakit_cts_adr = serial_port.port;

	log_printf(LOG_VERBOSE, "eakit_cts_init(): device:\t%s (COM%d)\tPort:\t0x%x\tIRQ:\t%d\n", config_getstr(EAKIT_DEVICE_STR, EAKIT_DEVICE), serial_port.line +1, serial_port.port, serial_port.irq);

	// set permissions
	ioperm(eakit_cts_adr + UART_MSR, 1, 1);

	eakit_cts_init_flag = TRUE;

	// das hier funktioniert
	eakit_cts_poll();

	return TRUE;
}

/**
 * deinit
 *
 */
int eakit_cts_deinit(void)
{
	log_printf(LOG_DEBUG, "eakit_cts_deinit(): deinitializing\n");

	ioperm(eakit_cts_adr + UART_MSR, 1, 0);
	close(eakit_cts_fd);

	eakit_cts_init_flag = TRUE;

	return TRUE;
}

/**
 * poll
 *
 */
void eakit_cts_poll(void)
{
	int msr = 0;

	// hier kassiere ich einen seg-fault
	msr = inb(eakit_cts_adr + UART_MSR);
	eakit_cts_ready = (msr & UART_MSR_CTS) ? TRUE : FALSE;

	printf("cts = %d\n", eakit_cts_ready);
}

hier ein auszug aus dem hauptprogramm:

// init cts-check
	if(eakit_cts_init() == FALSE) {
		log_printf(LOG_ERROR, "eakit_cts_init(): failed!\n");
		exit(0);
	}

	// poll cts-line
	if(pthread_create(&pt_cts, NULL, (void *)&main_thread_cts, NULL) != 0) {
		log_printf(LOG_ERROR, "error creating thread: cts!\n");
		exit(0);
	}

und hier die funktion für den thread

void main_thread_cts(void)
{
	sigset_t mask;

	log_printf(LOG_DEBUG, "main_thread_cts(): started thread with id %ld\n", pthread_self());

	// ignore signals
	sigemptyset(&mask);
	sigaddset(&mask, SIGINT);
	sigaddset(&mask, SIGTERM);
	sigaddset(&mask, SIGHUP);

	if((pthread_sigmask(SIG_BLOCK, &mask, NULL)) != 0) {
		log_printf(LOG_ERROR, "main_thread_cts(): error creating signal-mask\n");
		return;
	}

	// loop
	while(terminate == FALSE) {
		eakit_cts_poll();

		usleep(5000);
	}

	log_printf(LOG_NOISYDEBUG, "main_thread_cts(): thread %ld shutting down\n", pthread_self());

	// exit;
	pthread_exit((void *)0);
}

das problem: rufe ich die funktion eakit_cts_poll() in dem thread auf, kassiere ich einen seg-fault, rufe ich die funktion oben in der init-funktion auf, funktioniert das ganze *planlos*

hoffe mir kann jemand auf die sprünge helfen