Hello list, I try to handle some ioctl by my ldisc driver. Especially ioctl TCSBRK. After wondering why I didn't receive TCSBRK ioctl I stumbled accros this comments: include/linux/tty_ldisc.h * int (*ioctl)(struct tty_struct * tty, struct file * file, * unsigned int cmd, unsigned long arg); * * This function is called when the user requests an ioctl which * is not handled by the tty layer or the low-level tty driver. * It is intended for ioctls which affect line discpline * operation. Note that the search order for ioctls is (1) tty * layer, (2) tty low-level driver, (3) line discpline. So a * low-level driver can "grab" an ioctl request before the line * discpline has a chance to see it. and the corresponding tty_ioctl() implementation in tty_io.c. Am I correct that the TCSBRK is grabbed here before receiving it in any ldisc driver code? Is there a way to change the order without major changes in the tty_io.c code? I want to intercept the TCSBRK because my hardware needs some handling here and for userspace applications it should be transparent. Best regards, Oliver