Wait queue crash

[Suresh Thennarangam]

We are having this problem with wait queues on linux 2.3.28 kernel
(and 2.2.12 as well)
The code is simple .. and it crashes. I can see other code in
the linux usb stack using exactly the same thing. Does anyone 
have a clue ?  I've read about reentrancy issues but the code
here doesn't really do much. Thanks for your input.

Suresh/

static struct tq_struct        mc_tq_task = { 0, 0, 0, 0 };
static  wait_queue_head_t      mc_tq_wait;

void    defered_proc(void * ptr)
{

    // do some context specific stuff here ..
   
   wake_up_interruptible( &mc_tq_wait);
}

static void     intr_handler(void *ptr)
{
 
   mc_tq_task.routine = defered_proc;
   mc_tq_task.data    = dev;

   init_waitqueue_head(&mc_tq_wait);
 
   queue_task(&mc_tq_task, &tq_scheduler);
   interruptible_sleep_on(&mc_tq_wait);

}