--- to-linus-2.5/arch/ia64/kernel/mca.c~	2003-08-05 09:03:02.000000000 -0600
+++ to-linus-2.5/arch/ia64/kernel/mca.c	2003-08-05 09:05:03.000000000 -0600
@@ -1149,13 +1149,19 @@
 
 			printk(KERN_WARNING "%s: Returning to interrupt driven CMC handler\n", __FUNCTION__);
 
-			cmc_polling_enabled = 0;
 			/*
 			 * The cmc interrupt handler enabled irqs, so
 			 * this can't deadlock.
 			 */
 			smp_call_function(ia64_mca_cmc_vector_enable, NULL, 1, 0);
+
+			/*
+			 * Turn off interrupts before re-enabling the
+			 * cmc vector locally.  Make sure we get out.
+			 */
+			local_irq_disable();
 			ia64_mca_cmc_vector_enable(NULL);
+			cmc_polling_enabled = 0;
 
 		} else {