read call blocks

[user20000]

Hi,
im new on writing device driver in kernelspace.
So i started with writung a small scull driver.

The problem is, that a write call blocks sthe system.
I do not know why.

Here the function.

ssize_t FS_write(struct file * filp, const char * buf, size_t count, loff_t * f_pos)
{
if(down_interruptible(&dev->sem))
{
return -1;
}

// Tha array is big enough
copy_from_user(data_array,buf,count);

*f_pos+=count;

up(&dev->sem)

return count;

}

I dont know what why the driver hangs
I call
"Hallo" > /dev/mydriver

i then i can see that the init is done well.
After it, the kernel hangs.

Tank you for help.

[user20000]

Okay, sorry i have it now
The Read call was is well done.

It hangs on a secial call of the open of my driver.
I have implemented some personalities and there had beeen a buck while
chanching the file operations structure.

Thanks

[Rubberman]

Sometimes the best help is none... Glad you sorted it out.

[vich00ss]

Welldone......