patch-2.0.36 linux/arch/i386/kernel/irq.c

• Lines: 31
• Date: Sun Nov 15 10:32:46 1998
• Orig file: v2.0.35/linux/arch/i386/kernel/irq.c
• Orig date: Mon Mar 17 14:58:59 1997

diff -u --recursive --new-file v2.0.35/linux/arch/i386/kernel/irq.c linux/arch/i386/kernel/irq.c
@@ -345,7 +345,29 @@
 {
 	struct irqaction * action = *(irq + irq_action);
 	int do_random = 0;
-
+	int c,intm,mask;
+#ifdef IRQ_DEBUG
+	static int count;
+	if (smp_processor_id() != 0 && count++ < 1000)
+	  printk("IRQ %d: done by CPU %d\n",irq,smp_processor_id());
+#endif	  
+	if (irq  >= 8) {
+	  c = cache_A1;
+	  intm = inb(0xA1);
+	  mask =  1 << (irq - 8);
+	} else {
+	  c = cache_21;
+	  intm = inb(0x21);
+	  mask =  1 << irq;
+	}
+	if (!(c & mask) || !(intm & mask)) {
+#ifdef IRQ_DEBUG	
+	  printk("IRQ %d (proc %d):cache_x1=0x%x,INT mask=0x%x\n", irq, smp_processor_id(),c,intm);
+#endif	  
+	  /* better to return because the interrupt may be asserted again,
+	     the bad thing is that we may loose some interrupts */
+	  return;
+	}
 #ifdef __SMP__
 	if(smp_threads_ready && active_kernel_processor!=smp_processor_id())
 		panic("IRQ %d: active processor set wrongly(%d not %d).\n", irq, active_kernel_processor, smp_processor_id());