--- old/drivers/scsi/sata_qstor.c	2006-09-19 23:42:06.000000000 -0400
+++ linux/drivers/scsi/sata_qstor.c	2006-11-06 09:50:02.000000000 -0500
@@ -459,6 +459,7 @@
 {
 	struct ata_host_set *host_set = dev_instance;
 	unsigned int handled = 0;
+	static int spurious = 0;
 
 	VPRINTK("ENTER\n");
 
@@ -466,6 +467,20 @@
 	handled  = qs_intr_pkt(host_set) | qs_intr_mmio(host_set);
 	spin_unlock(&host_set->lock);
 
+	/* There are reports of at least one system with glitchy interrupts,
+	 * and if we return !handled here for those then the kernel may totally
+	 * disable our own IRQ line (duh!).
+	 * So, try and be tolerant, but not *too* tolerant.
+	 */
+	if (!handled) {
+		if (spurious < 10) {
+			printk("sata_qstor: spurious=%d\n", spurious);
+			++spurious;
+			handled = 1;
+		}
+	} else if (spurious)
+		--spurious;
+
 	VPRINTK("EXIT\n");
 
 	return IRQ_RETVAL(handled);