[PATCH] VM86 interrupt emulation fix

Fixes faulty IRQ_NONE value returning by VM86 irq_handler().

The IRQ source is blocked as well until userspace confirms processing.
This should enable to use VM86 code even for level triggered interrupt
sources. 
Signed-off-by: Pavel Pisa <pisa@cmp.felk.cvut.cz>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/i386/kernel/vm86.c

@@ -723,7 +723,14 @@ static irqreturn_t irq_handler(int intno, void *dev_id, struct pt_regs * regs)
 	irqbits |= irq_bit;
 	if (vm86_irqs[intno].sig)
 		send_sig(vm86_irqs[intno].sig, vm86_irqs[intno].tsk, 1);
-	/* else user will poll for IRQs */
+	spin_unlock_irqrestore(&irqbits_lock, flags);
+	/*
+	 * IRQ will be re-enabled when user asks for the irq (whether
+	 * polling or as a result of the signal)
+	 */
+	disable_irq(intno);
+	return IRQ_HANDLED;
+
 out:
 	spin_unlock_irqrestore(&irqbits_lock, flags);	
 	return IRQ_NONE;