--- a/sys/src/9/pc/trap.c
+++ b/sys/src/9/pc/trap.c
@@ -356,7 +355,7 @@ trap(Ureg* ureg)
 			if(ctl->irq == IrqCLOCK || ctl->irq == IrqTIMER)
 				clockintr = 1;
 
-			if(up && !clockintr)
+			if(up && !clockintr && m->ilockdepth == 0)
 				preempted();
 		}
 	}
@@ -435,7 +434,7 @@ trap(Ureg* ureg)
 	splhi();
 
 	/* delaysched set because we held a lock or because our quantum ended */
-	if(up && up->delaysched && clockintr){
+	if(up && up->delaysched && clockintr && m->ilockdepth == 0){
 		sched();
 		splhi();
 	}
--- a/sys/src/9/pc/x86watchdog.c
+++ b/sys/src/9/pc/x86watchdog.c
@@ -133,8 +133,10 @@ x86wdenable(void)
 		break;
 	case P4:
 		rdmsr(0x1A0, &r);
-		if(!(r & 0x0000000000000080LL))
-			return;
+		if(!(r & 0x0000000000000080LL)){
+			iunlock(wd);
+			error(Enodev);
+		}
 	
 		for(i = 0; i < 18; i++)
 			wrmsr(0x300+i, 0);		/* perfctr */