[vdr] Problems tuning DVB-t cards

["Simon Dean" <linux-dvb@sickhack.com>]

I have been experiencing problems tuning either of my two DVB-t cards.  

After a "make rmsmod;make insmod" of the drivers the following code will
fail to tune either my full DVB-t card or my budget DVB-t card.  If I
use dvbtune (http://www.linuxstb.org/dvbtune/) to tune either card and
then run the following code, the following code succeeds in tuning the
card.  

In summary the following card will fail to tune a DVB-t card after a
fresh driver load/reload but will succeed in tuning a card if it has
first been successfully tuned using a different program.  Is there a
quirk/bug of the DVB drivers that I am not aware of that stops this code
from functioning?  

If I tune the first card with dvbtune and then try my code on the second
card, my code still fails.  

I have posted this message to the VDR mailing list, as opposed to just
the linux-dvb mailing list, because VDR also fails to tune either of my
cards if I have not first ran dvbtune on them both.  

Thanks, 

Simon 


#define FRONTEND_DEV "/dev/ost/frontend"
#define FREQUENCY 754166667
#define POLL_EVENTS POLLIN
#define MAX_TRIES 5

#include <fcntl.h>
#include <stdio.h>
#include <sys/poll.h>
#include <sys/ioctl.h>
#include <unistd.h>

// DVB includes
#include <ost/frontend.h>

int main(int argc, char *argv[])
{
    int fd;
    struct pollfd pollFds[1];
    FrontendParameters params;
    int i;

    params.Frequency = FREQUENCY;
    params.u.ofdm.bandWidth = BANDWIDTH_8_MHZ;
    params.u.ofdm.HP_CodeRate = FEC_2_3;
    params.u.ofdm.LP_CodeRate = FEC_1_2;
    params.u.ofdm.Constellation = QAM_64;
    params.u.ofdm.TransmissionMode = TRANSMISSION_MODE_2K;
    params.u.ofdm.guardInterval = GUARD_INTERVAL_1_32;
    params.u.ofdm.HierarchyInformation = HIERARCHY_NONE;
    
    if ((fd = open(FRONTEND_DEV, O_RDWR)) < 0)
    {
        perror("pollFds");
        return -1;
    }

    for (i = 0; i < MAX_TRIES; i++)
    {
        if (ioctl(fd, FE_SET_FRONTEND, &params) < 0) 
        {
            perror("FE_SET_FRONTEND");
            return -1;
        }

        pollFds[0].fd = fd;
        pollFds[0].events = POLL_EVENTS;
        
        if (poll(pollFds, 1, 10000))
        {
            if (pollFds[0].revents & POLL_EVENTS)
            {
                FrontendEvent event;

                if (ioctl(fd, FE_GET_EVENT, &event) == -EBUFFEROVERFLOW)
                {
                    perror("FE_GET_EVENT");
                    return -1;
                }

                switch(event.type)
                {
                case FE_UNEXPECTED_EV:
                    printf("FE_UNEXPECTED_EV\n");
                    break;
                case FE_FAILURE_EV:
                    printf("FE_FAILURE_EV\n");
                    break;
                case FE_COMPLETION_EV:
                    printf("FE_COMPLETION_EV\n");
                    break;
                }

                if (event.type == FE_COMPLETION_EV) break;
            }
            else
            {
                printf("ERROR: revents.\n");
                return -1;
            }
        }
        else
        {
            printf("ERROR: Timeout.\n");
        }
    }    

    close(fd);
    
    return 0;
}