Hi folks, Its been a while since i last did some kernel related stuff, so please bear with me if this sounds strange to your ears. What i want to achieve: I want to implement a hardware trigger that a user space process can react on. I need a driver that blocks a process/thread until a sepcific hardware interrupt occurs. The process should call a kernel interface and then should get blocked until another process/thread calls another kernel interface to stop waiting for the irq or an interrupt actually occurs. What i have: Back in the days i wrote a little character driver which implemented 2 ioctl commands. One command (IOCTL_TRIGGER_WAIT_IRQ) put the calling process to sleep using wait_evemt_interruptible() and the other command (IOCTL_TRIGGER_STOP_WAIT_IRQ) woke a processes again by calling wake_up_interruptible(). Now ioctls are frowned upon and i do not want to mess with majors and minors anymore either. Do you have any hints to the right approach for such a driver? Should i use some sysfs interface? If yes, which? Or does such a driver already exist? Can it be one completely in user space? puzzled. cheers, Andre