Module Name: src
Committed By: knakahara
Date: Thu Feb 2 10:29:10 UTC 2017
Modified Files:
src/sys/dev/pci: if_wm.c
Log Message:
remove WM_CORE_LOCK in deferred start routine.
It is enough to check each txq's txq_stopping with
mutex_enter(not mutex_tryenter).
reviewed by ozaki-r@n.o.
To generate a diff of this commit:
cvs rdiff -u -r1.475 -r1.476 src/sys/dev/pci/if_wm.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/dev/pci/if_wm.c
diff -u src/sys/dev/pci/if_wm.c:1.475 src/sys/dev/pci/if_wm.c:1.476
--- src/sys/dev/pci/if_wm.c:1.475 Wed Feb 1 08:56:41 2017
+++ src/sys/dev/pci/if_wm.c Thu Feb 2 10:29:10 2017
@@ -1,4 +1,4 @@
-/* $NetBSD: if_wm.c,v 1.475 2017/02/01 08:56:41 msaitoh Exp $ */
+/* $NetBSD: if_wm.c,v 1.476 2017/02/02 10:29:10 knakahara Exp $ */
/*
* Copyright (c) 2001, 2002, 2003, 2004 Wasabi Systems, Inc.
@@ -84,7 +84,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_wm.c,v 1.475 2017/02/01 08:56:41 msaitoh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_wm.c,v 1.476 2017/02/02 10:29:10 knakahara Exp $");
#ifdef _KERNEL_OPT
#include "opt_net_mpsafe.h"
@@ -4720,6 +4720,9 @@ wm_turnon(struct wm_softc *sc)
KASSERT(WM_CORE_LOCKED(sc));
+ /*
+ * must unset stopping flags in ascending order.
+ */
for(i = 0; i < sc->sc_nqueues; i++) {
struct wm_txqueue *txq = &sc->sc_queue[i].wmq_txq;
struct wm_rxqueue *rxq = &sc->sc_queue[i].wmq_rxq;
@@ -4745,6 +4748,9 @@ wm_turnoff(struct wm_softc *sc)
sc->sc_core_stopping = true;
+ /*
+ * must set stopping flags in ascending order.
+ */
for(i = 0; i < sc->sc_nqueues; i++) {
struct wm_rxqueue *rxq = &sc->sc_queue[i].wmq_rxq;
struct wm_txqueue *txq = &sc->sc_queue[i].wmq_txq;
@@ -7334,22 +7340,23 @@ wm_deferred_start(struct ifnet *ifp)
* Try to transmit on all Tx queues. Passing a txq somehow and
* transmitting only on the txq may be better.
*/
-restart:
- WM_CORE_LOCK(sc);
- if (sc->sc_core_stopping)
- goto out;
-
for (; qid < sc->sc_nqueues; qid++) {
struct wm_txqueue *txq = &sc->sc_queue[qid].wmq_txq;
- if (!mutex_tryenter(txq->txq_lock))
- continue;
-
+ /*
+ * We must mutex_enter(txq->txq_lock) instead of
+ * mutex_tryenter(txq->txq_lock) here.
+ * mutex_tryenter(txq->txq_lock) would fail as this txq's
+ * txq_stopping flag is being set. In this case, this device
+ * begin to stop, so we must not start any Tx processing.
+ * However, it may start Tx processing for sc_queue[qid+1]
+ * if we use mutex_tryenter() here.
+ */
+ mutex_enter(txq->txq_lock);
if (txq->txq_stopping) {
mutex_exit(txq->txq_lock);
- continue;
+ return;
}
- WM_CORE_UNLOCK(sc);
if ((sc->sc_flags & WM_F_NEWQUEUE) != 0) {
/* XXX need for ALTQ */
@@ -7363,12 +7370,7 @@ restart:
wm_transmit_locked(ifp, txq);
}
mutex_exit(txq->txq_lock);
-
- qid++;
- goto restart;
}
-out:
- WM_CORE_UNLOCK(sc);
}
/* Interrupt */
