Serial Port Internal Loopback in 2.6 Kernel

Hi all,

I have been working in a diagnostics development for 2.4 & 2.6 Kernels.

I have a specific issue in doing internal loopback in 2.6 kernel. In
2.4 kernels I have used the TIOCMSET ioctl for setting the Modem
Control Register (TIOCM_LOOP Bit). But the same doesnt work for 2.6
kernels.

Is there any specific reason for this ?

Also it has been said that in 2.6 kernel they have implemented the
function callbacks..instead of ioctls..(But still I can find the ioctl
function in the driver)


int (*tiocmget)(struct tty_struct *tty,
                struct file *file);
int (*tiocmset)(struct tty_struct *tty,
                struct file *file,
                unsigned int set,
                unsigned int clear);

How to use these functions from user space ?

Please provide some input on this..

Thanks and Regards,
Sudhakar V