It worked as root, so I did the chmod. Thanks for the help.
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Can't make communication between user application and usb device driver work
I have a usb device driver for an RFID reader/writer, but I can't get communication to work between a user application and the driver. The driver module loads in the kernel just fine, but when I run the open command in the user app. I get an error:
fd = open ("/dev/rfid0", O_RDWR);
if (fd == -1)
{
printf("open error...\n");
exit(0);
}
this always returns an error. Any ideas?
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by: person1994Posted on 2005-09-08 at 10:14:13ID: 14846304
Do you have the correct permission on /dev/rfid0? Try running your app with super user privilage and see if you still get the same problem.
If the open system works in superuser (root), then do chmod +rw /dev/rfid0.
If that does not work, try doing a perror("open") inside your if statment. This will give a more accurate description of the error.
Good luck