1 files changed, 27 insertions, 17 deletions

diff --git a/drivers/xen/xenbus/xenbus_comms.c b/drivers/xen/xenbus/xenbus_comms.c
index 6efbe3f29ca..fdb0f339d0a 100644
--- a/drivers/xen/xenbus/xenbus_comms.c
+++ b/drivers/xen/xenbus/xenbus_comms.c
@@ -30,6 +30,8 @@
  * IN THE SOFTWARE.
  */
 
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
 #include <linux/wait.h>
 #include <linux/interrupt.h>
 #include <linux/sched.h>
@@ -203,31 +205,39 @@ int xb_read(void *data, unsigned len)
 int xb_init_comms(void)
 {
 	struct xenstore_domain_interface *intf = xen_store_interface;
-	int err;
 
 	if (intf->req_prod != intf->req_cons)
-		printk(KERN_ERR "XENBUS request ring is not quiescent "
-		       "(%08x:%08x)!\n", intf->req_cons, intf->req_prod);
+		pr_err("request ring is not quiescent (%08x:%08x)!\n",
+		       intf->req_cons, intf->req_prod);
 
 	if (intf->rsp_prod != intf->rsp_cons) {
-		printk(KERN_WARNING "XENBUS response ring is not quiescent "
-		       "(%08x:%08x): fixing up\n",
-		       intf->rsp_cons, intf->rsp_prod);
-		intf->rsp_cons = intf->rsp_prod;
+		pr_warn("response ring is not quiescent (%08x:%08x): fixing up\n",
+			intf->rsp_cons, intf->rsp_prod);
+		/* breaks kdump */
+		if (!reset_devices)
+			intf->rsp_cons = intf->rsp_prod;
 	}
 
-	if (xenbus_irq)
-		unbind_from_irqhandler(xenbus_irq, &xb_waitq);
+	if (xenbus_irq) {
+		/* Already have an irq; assume we're resuming */
+		rebind_evtchn_irq(xen_store_evtchn, xenbus_irq);
+	} else {
+		int err;
+		err = bind_evtchn_to_irqhandler(xen_store_evtchn, wake_waiting,
+						0, "xenbus", &xb_waitq);
+		if (err < 0) {
+			pr_err("request irq failed %i\n", err);
+			return err;
+		}
 
-	err = bind_evtchn_to_irqhandler(
-		xen_store_evtchn, wake_waiting,
-		0, "xenbus", &xb_waitq);
-	if (err <= 0) {
-		printk(KERN_ERR "XENBUS request irq failed %i\n", err);
-		return err;
+		xenbus_irq = err;
 	}
 
-	xenbus_irq = err;
-
 	return 0;
 }
+
+void xb_deinit_comms(void)
+{
+	unbind_from_irqhandler(xenbus_irq, &xb_waitq);
+	xenbus_irq = 0;
+}