Re: Interrupt trouble due to IRQ router VIA?

[Alan Cox]

On Wed, 2002-07-31 at 21:15, Kathy Frazier wrote:
> another system.  In this system, the driver times out on the 
> interruptible_sleep_on_timeout waiting for the interrupt.  One thing that I 

There is a classic kernel programming error which goes something like
this

my_interrupt()
{
	foo->ready = 1;
	wake_up(&foo_pending);
}

foo_read()
{
	while(!foo->ready && !signal_pending(current))
		interruptible_sleep_on(&foo_pending);

}

What happens then is this

	foo->ready = 0 - true
	signal pending = 0 - ok

		INTERRUPT
			foo->ready=1
			wake up
		END INTERRUPT

	interruptible_sleep_on(&foo_pending);

Waits forever

It could be your timings have changed so such a bug now shows up