Release interrupt source if the interrupt task is already scheduled

Tested by Imre Oolberg, thanks!

diff --git a/sys/dev/pv/xen.c b/sys/dev/pv/xen.c
index 3555f83..a2a6353 100644 (file)
--- a/sys/dev/pv/xen.c
+++ b/sys/dev/pv/xen.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: xen.c,v 1.92 2018/01/21 18:51:19 mikeb Exp $  */
+/*     $OpenBSD: xen.c,v 1.93 2018/01/21 18:54:46 mikeb Exp $  */
 
 /*
  * Copyright (c) 2015, 2016, 2017 Mike Belopuhov
@@ -600,7 +600,7 @@ xen_intsrc_add(struct xen_softc *sc, struct xen_intsrc *xi)
 static inline struct xen_intsrc *
 xen_intsrc_acquire(struct xen_softc *sc, evtchn_port_t port)
 {
-       struct xen_intsrc *xi;
+       struct xen_intsrc *xi = NULL;
 
        mtx_enter(&sc->sc_islck);
        SLIST_FOREACH(xi, &sc->sc_intrs, xi_entry) {
@@ -713,8 +713,10 @@ xen_intr_schedule(xen_intr_handle_t xih)
        struct xen_softc *sc = xen_sc;
        struct xen_intsrc *xi;
 
-       if ((xi = xen_intsrc_acquire(sc, (evtchn_port_t)xih)) != NULL)
-               task_add(xi->xi_taskq, &xi->xi_task);
+       if ((xi = xen_intsrc_acquire(sc, (evtchn_port_t)xih)) != NULL) {
+               if (!task_add(xi->xi_taskq, &xi->xi_task))
+                       xen_intsrc_release(sc, xi);
+       }
 }
 
 /*