Hi,
Thanks.

Isn't this supposed to be called /dev/mymisc ?

Well, your are right ! and with  /dev/mymisc it worked!
sorry for the noise.

BTW, it worked also without  implementing the open() method


rgs
K.

On Wed, Dec 19, 2012 at 10:51 AM, Daniel Baluta [off-list ref] wrote:

On Wed, Dec 19, 2012 at 10:36 AM, Kevin Wilson [off-list ref] wrote:

quoted

Hello,kernelnewbies

I am trying to develop a misc driver in 3.7.0 kernel.

As a basis I copy and paste this code, *without any change*,

http://virtlog.com/2008/03/25/linux-miscdevice-sample/

And build it.
after insmod I have :
[root at n miscDevice]\>ls -al /dev/mymisc
crw------- 1 root root 10, 59 Dec 19 10:24 /dev/mymisc


However, when trying to open this file I get:
open: No such file or directory

Any ideas why ?

You should implement open. Check this out [1]

quoted

The program with which I try to open the device is simple, a few lines
following here:
int main()
{
  int fd;

  fd = open("/dev/mymodule", O_RDONLY);

Isn't this supposed to be called /dev/mymisc ?

quoted

        if (fd == -1) {
                perror("open");
                exit(1);
        }
  printf("open succeeded\n");

}

thanks,
Daniel.

[1] http://lxr.linux.no/#linux+v3.7.1/drivers/char/efirtc.c#L282