--- 752b362bf651d7e1bdf84a3f54601ddf863e8b12
+++ 7c37ec359ec29ad40fc2cf47642316ac3cbba8bc
@@ -29,17 +29,21 @@ static void __udelay_disabled(unsigned l
 {
 	unsigned long mask, cr0, cr0_saved;
 	u64 clock_saved;
+	u64 end;
 
+	mask = psw_kernel_bits | PSW_MASK_WAIT | PSW_MASK_EXT;
+	end = get_clock() + (usecs << 12);
 	clock_saved = local_tick_disable();
-	set_clock_comparator(get_clock() + (usecs << 12));
 	__ctl_store(cr0_saved, 0, 0);
 	cr0 = (cr0_saved & 0xffff00e0) | 0x00000800;
 	__ctl_load(cr0 , 0, 0);
-	mask = psw_kernel_bits | PSW_MASK_WAIT | PSW_MASK_EXT;
 	lockdep_off();
-	trace_hardirqs_on();
-	__load_psw_mask(mask);
-	local_irq_disable();
+	do {
+		set_clock_comparator(end);
+		trace_hardirqs_on();
+		__load_psw_mask(mask);
+		local_irq_disable();
+	} while (get_clock() < end);
 	lockdep_on();
 	__ctl_load(cr0_saved, 0, 0);
 	local_tick_enable(clock_saved);