Question : problem using ioctl , CDROM_DRIVE_STATUS

Hi,
I'm using the ubuntu version of Linux and C++.  I'm trying to use ioctl to detect the status of the cdrom drive.  according to the documentation http://www.mjmwired.net/kernel/Documentation/ioctl/cdrom.txt (line 682) CDROM_DRIVE_STATUS should return one of 5 states:

CDS_NO_INFO      
CDS_NO_DISC
CDS_TRAY_OPEN
CDS_DRIVE_NOT_READY
CDS_DISC_OK

I have only been able to detect two states: CDS_DISC_OK and CDS_TRAY_OPEN.  I'm getting CDS_TRAY_OPEN when there is no disc in the drive, even when the tray is closed.  I need to know if the tray is closed but there is no disc in the drive.  Is there something I'm doing wrong (my code is below)?


Thanks,
Nick



#include
#include
#include
#include
#include
#include
#include
#include
#include
#include


using std::cout;
using std::endl;





int main(char** argv)
{

    int fd;
    int ret,d;


    while(1)
    {
    if ((fd = open("/dev/cdrom",O_RDONLY | O_NONBLOCK)) < 0) {
        perror("open");
        exit(1);
    }
   
   
      ret = ioctl(fd,CDROM_DRIVE_STATUS,0);

      cout<
      switch(ret) {
      case CDS_NO_INFO:
          cout<<"CDS_NO_INFO"<
          break;
      case CDS_NO_DISC:
          cout<<"CDS_NO_DISC"<
          break;
      case CDS_TRAY_OPEN:
          cout<<"CDS_TRAY_OPEN"<l;
          d = ioctl(fd,CDROM_DISC_STATUS,0);
          cout<          break;
      case CDS_DRIVE_NOT_READY:
          cout<<"CDS_DRIVE_NOT_READY"<          break;
      case CDS_DISC_OK:
          cout<<"CDS_DISC_OK"<
          d = ioctl(fd,CDROM_DISC_STATUS,0);
          cout<          switch(d){
          case CDS_NO_INFO:
            cout<<"CDS_NO_INFO"<
            break;
          case CDS_AUDIO:
            cout<<"CDS_AUDIO"<            break;
          case CDS_XA_2_2:
            cout<<"CDS_XA_2_2"<            break;
          case CDS_XA_2_1:
            cout<<"CDS_XA_2_1"<            break;
          case CDS_DATA_1:
            cout<<"CDS_DATA_1"<            break;
          case CDS_MIXED:
            cout<<"CDS_MIXED"<            break;
          default:
            cout<<"SUPER ERROR 2"<          }
          break;
      case -1:
          cout<<"ERROR"<          cout<          switch(errno) {
          case ENOSYS:
            cout<<"ENOSYS"<            break;
          case EINVAL:
            cout<<"EINVAL"<            break;
          case ENOMEM:
            cout<<"ENOMEM"<            break;
          default:
            cout<<"ERRNO ERROR"<          }
          break;
      default:
          cout<<"SUPER ERROR"<      }
      usleep(100);
    }
    return 0;

}

Answer : problem using ioctl , CDROM_DRIVE_STATUS

>> does anybody know when a CDS_DRIVE_NOT_READY state occurs

It means the drive is busy and cannot accept any commands given to it. It might be busy working on previous command like reading data etc.

this cdrom howto might be helpful to you.
http://www.faqs.org/docs/Linux-HOWTO/CDROM-HOWTO.html

If you like to know the CDROM detals, see the spec. for atapi it is www.t13.org.


regards
Manish Regmi