Commit 46b0cc9f authored by Ido Yariv's avatar Ido Yariv Committed by Luciano Coelho
Browse files

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: default avatarIdo Yariv <ido@wizery.com>
Signed-off-by: default avatarLuciano Coelho <coelho@ti.com>
parent a454969e

drivers/net/wireless/wl12xx/main.c

+28 −2
Original line number Diff line number Diff line
@@ -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);