My driver write routine is not working properly.
As a result, when I do echo "123" > /dev/eater, the process is stopping and
the control goes into an infinite loop.
lsmod showed my driver was in use by 2 processes.
Now if i want to forcefully remove my driver module from kernel, how to do
that?
Below is the write routine:
static int eater_write(struct file *file, const char *buf, size_t lbuf,
loff_t *ppos)
{
int actual_data_allowed_to_write;
int data_written;
int data_to_copy=0;
printk("requested bytes to write: %d\n", lbuf);
actual_data_allowed_to_write = MAXSIZE - *ppos;
printk("allowed bytes to write: %d\n",
actual_data_allowed_to_write);
if(actual_data_allowed_to_write == 0)
{
printk("Device has no space to write. format it\n");
return(actual_data_allowed_to_write);
}
//if available space can accommodate data to write
if(actual_data_allowed_to_write > lbuf)
data_to_copy=lbuf;
//if available space can't accommodate date to write
if(actual_data_allowed_to_write < lbuf)
data_to_copy=actual_data_allowed_to_write;
printk("data_to_copy: %d\n", data_to_copy);
data_written=copy_from_user(eater_space + *ppos, /* to */ \
buf, /* from */ \
data_to_copy);
//update device memory with new position
*ppos += data_to_copy;
printk("\nWrote %d bytes\n", data_written);
return(data_written);
}
Appreciate any help.
/Sri.
