From a9e5ca2b2ad4fb4dd04dd121dd2515e91deb4aff Mon Sep 17 00:00:00 2001
From: tb <tb@openbsd.org>
Date: Thu, 4 Jan 2018 11:02:57 +0000
Subject: [PATCH] Back out tx mitigation again because it breaks suspend and
 resume at least on x230 and x240. Problem noted by claudio on icb.

ok dlg
---
 sys/net/ifq.c | 43 +------------------------------------------
 sys/net/ifq.h | 11 +++++++----
 2 files changed, 8 insertions(+), 46 deletions(-)

diff --git a/sys/net/ifq.c b/sys/net/ifq.c
index 6b71376a1b4..99b4704f8d0 100644
--- a/sys/net/ifq.c
+++ b/sys/net/ifq.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ifq.c,v 1.20 2018/01/02 07:08:10 dlg Exp $ */
+/*	$OpenBSD: ifq.c,v 1.21 2018/01/04 11:02:57 tb Exp $ */
 
 /*
  * Copyright (c) 2015 David Gwynne <dlg@openbsd.org>
@@ -70,16 +70,9 @@ struct priq {
 void	ifq_start_task(void *);
 void	ifq_restart_task(void *);
 void	ifq_barrier_task(void *);
-void	ifq_bundle_task(void *);
 
 #define TASK_ONQUEUE 0x1
 
-static inline void
-ifq_run_start(struct ifqueue *ifq)
-{
-	ifq_serialize(ifq, &ifq->ifq_start);
-}
-
 void
 ifq_serialize(struct ifqueue *ifq, struct task *t)
 {
@@ -120,16 +113,6 @@ ifq_is_serialized(struct ifqueue *ifq)
 	return (ifq->ifq_serializer == curcpu());
 }
 
-void
-ifq_start(struct ifqueue *ifq)
-{
-	if (ifq_len(ifq) >= min(4, ifq->ifq_maxlen)) {
-		task_del(ifq->ifq_softnet, &ifq->ifq_bundle);
-		ifq_run_start(ifq);
-	} else
-		task_add(ifq->ifq_softnet, &ifq->ifq_bundle);
-}
-
 void
 ifq_start_task(void *p)
 {
@@ -153,32 +136,12 @@ ifq_restart_task(void *p)
 	ifp->if_qstart(ifq);
 }
 
-void
-ifq_bundle_task(void *p)
-{
-	struct ifqueue *ifq = p;
-
-	ifq_run_start(ifq);
-}
-
 void
 ifq_barrier(struct ifqueue *ifq)
 {
 	struct cond c = COND_INITIALIZER();
 	struct task t = TASK_INITIALIZER(ifq_barrier_task, &c);
 
-	if (!task_del(ifq->ifq_softnet, &ifq->ifq_bundle)) {
-		int netlocked = (rw_status(&netlock) == RW_WRITE);
-
-		if (netlocked) /* XXXSMP breaks atomicity */
-			NET_UNLOCK();
-
-		taskq_barrier(ifq->ifq_softnet);
-
-		if (netlocked)
-			NET_LOCK();
-	}
-
 	if (ifq->ifq_serializer == NULL)
 		return;
 
@@ -203,7 +166,6 @@ void
 ifq_init(struct ifqueue *ifq, struct ifnet *ifp, unsigned int idx)
 {
 	ifq->ifq_if = ifp;
-	ifq->ifq_softnet = net_tq(ifp->if_index);
 	ifq->ifq_softc = NULL;
 
 	mtx_init(&ifq->ifq_mtx, IPL_NET);
@@ -225,7 +187,6 @@ ifq_init(struct ifqueue *ifq, struct ifnet *ifp, unsigned int idx)
 	mtx_init(&ifq->ifq_task_mtx, IPL_NET);
 	TAILQ_INIT(&ifq->ifq_task_list);
 	ifq->ifq_serializer = NULL;
-	task_set(&ifq->ifq_bundle, ifq_bundle_task, ifq);
 
 	task_set(&ifq->ifq_start, ifq_start_task, ifq);
 	task_set(&ifq->ifq_restart, ifq_restart_task, ifq);
@@ -277,8 +238,6 @@ ifq_destroy(struct ifqueue *ifq)
 {
 	struct mbuf_list ml = MBUF_LIST_INITIALIZER();
 
-	ifq_barrier(ifq); /* ensure nothing is running with the ifq */
-
 	/* don't need to lock because this is the last use of the ifq */
 
 	ifq->ifq_ops->ifqop_purge(ifq, &ml);
diff --git a/sys/net/ifq.h b/sys/net/ifq.h
index 345d1068594..3ce402b34c1 100644
--- a/sys/net/ifq.h
+++ b/sys/net/ifq.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ifq.h,v 1.19 2018/01/02 07:08:10 dlg Exp $ */
+/*	$OpenBSD: ifq.h,v 1.20 2018/01/04 11:02:57 tb Exp $ */
 
 /*
  * Copyright (c) 2015 David Gwynne <dlg@openbsd.org>
@@ -25,7 +25,6 @@ struct ifq_ops;
 
 struct ifqueue {
 	struct ifnet		*ifq_if;
-	struct taskq		*ifq_softnet;
 	union {
 		void			*_ifq_softc;
 		/*
@@ -58,7 +57,6 @@ struct ifqueue {
 	struct mutex		 ifq_task_mtx;
 	struct task_list	 ifq_task_list;
 	void			*ifq_serializer;
-	struct task		 ifq_bundle;
 
 	/* work to be serialised */
 	struct task		 ifq_start;
@@ -407,7 +405,6 @@ void		 ifq_attach(struct ifqueue *, const struct ifq_ops *, void *);
 void		 ifq_destroy(struct ifqueue *);
 void		 ifq_add_data(struct ifqueue *, struct if_data *);
 int		 ifq_enqueue(struct ifqueue *, struct mbuf *);
-void		 ifq_start(struct ifqueue *);
 struct mbuf	*ifq_deq_begin(struct ifqueue *);
 void		 ifq_deq_commit(struct ifqueue *, struct mbuf *);
 void		 ifq_deq_rollback(struct ifqueue *, struct mbuf *);
@@ -443,6 +440,12 @@ ifq_is_oactive(struct ifqueue *ifq)
 	return (ifq->ifq_oactive);
 }
 
+static inline void
+ifq_start(struct ifqueue *ifq)
+{
+	ifq_serialize(ifq, &ifq->ifq_start);
+}
+
 static inline void
 ifq_restart(struct ifqueue *ifq)
 {
-- 
2.20.1