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authorIdo Yariv <ido@wizery.com>2012-01-11 07:42:41 (GMT)
committerLuciano Coelho <coelho@ti.com>2012-02-15 06:38:28 (GMT)
commit46b0cc9ffce356fbcb2135219a3ed8500714a9e4 (patch)
tree3f7af09f3b7ff2380701eeb0764e170903182765 /drivers/net
parenta454969ede024a209e6a755d5f7a928ab81ed00c (diff)
downloadlinux-fsl-qoriq-46b0cc9ffce356fbcb2135219a3ed8500714a9e4.tar.xz
wl12xx: Fix potential interrupt storm
The interrupt threaded handler exits immediately if the driver's state is WL1271_STATE_OFF. As a result, the interrupt status is not read. If the interrupt is level triggered, it will be fired again. Fix this by disabling interrupts before setting the state to OFF. Signed-off-by: Ido Yariv <ido@wizery.com> Signed-off-by: Luciano Coelho <coelho@ti.com>
Diffstat (limited to 'drivers/net')
-rw-r--r--drivers/net/wireless/wl12xx/main.c30
1 files changed, 28 insertions, 2 deletions
diff --git a/drivers/net/wireless/wl12xx/main.c b/drivers/net/wireless/wl12xx/main.c
index 9e9fb3f..3a1636b 100644
--- a/drivers/net/wireless/wl12xx/main.c
+++ b/drivers/net/wireless/wl12xx/main.c
@@ -1397,9 +1397,23 @@ int wl1271_plt_stop(struct wl1271 *wl)
wl1271_notice("power down");
+ /*
+ * Interrupts must be disabled before setting the state to OFF.
+ * Otherwise, the interrupt handler might be called and exit without
+ * reading the interrupt status.
+ */
+ wl1271_disable_interrupts(wl);
mutex_lock(&wl->mutex);
if (wl->state != WL1271_STATE_PLT) {
mutex_unlock(&wl->mutex);
+
+ /*
+ * This will not necessarily enable interrupts as interrupts
+ * may have been disabled when op_stop was called. It will,
+ * however, balance the above call to disable_interrupts().
+ */
+ wl1271_enable_interrupts(wl);
+
wl1271_error("cannot power down because not in PLT "
"state: %d", wl->state);
ret = -EBUSY;
@@ -1411,7 +1425,6 @@ int wl1271_plt_stop(struct wl1271 *wl)
mutex_unlock(&wl->mutex);
- wl1271_disable_interrupts(wl);
wl1271_flush_deferred_work(wl);
cancel_work_sync(&wl->netstack_work);
cancel_work_sync(&wl->recovery_work);
@@ -1773,11 +1786,25 @@ static void wl1271_op_stop(struct ieee80211_hw *hw)
wl1271_debug(DEBUG_MAC80211, "mac80211 stop");
+ /*
+ * Interrupts must be disabled before setting the state to OFF.
+ * Otherwise, the interrupt handler might be called and exit without
+ * reading the interrupt status.
+ */
+ wl1271_disable_interrupts(wl);
mutex_lock(&wl->mutex);
if (wl->state == WL1271_STATE_OFF) {
mutex_unlock(&wl->mutex);
+
+ /*
+ * This will not necessarily enable interrupts as interrupts
+ * may have been disabled when op_stop was called. It will,
+ * however, balance the above call to disable_interrupts().
+ */
+ wl1271_enable_interrupts(wl);
return;
}
+
/*
* this must be before the cancel_work calls below, so that the work
* functions don't perform further work.
@@ -1789,7 +1816,6 @@ static void wl1271_op_stop(struct ieee80211_hw *hw)
list_del(&wl->list);
mutex_unlock(&wl_list_mutex);
- wl1271_disable_interrupts(wl);
wl1271_flush_deferred_work(wl);
cancel_delayed_work_sync(&wl->scan_complete_work);
cancel_work_sync(&wl->netstack_work);