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Commit e49cc34f authored by Sathya Perla's avatar Sathya Perla Committed by David S. Miller
Browse files

be2net: fix INTx ISR for interrupt behaviour on BE2 



On BE2 chip, an interrupt may be raised even when EQ is in un-armed state.
As a result be_intx()::events_get() and be_poll:events_get() can race and
notify an EQ wrongly.

Fix this by counting events only in be_poll(). Commit 0b545a62 fixes
the same issue in the MSI-x path.

But, on Lancer, INTx can be de-asserted only by notifying num evts. This
is not an issue as the above BE2 behavior doesn't exist/has never been
seen on Lancer.

Signed-off-by: default avatarSathya Perla <sathya.perla@emulex.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent f33e716f

drivers/net/ethernet/emulex/benet/be_main.c

+23 −31
Original line number Diff line number Diff line
@@ -1675,24 +1675,6 @@ static inline int events_get(struct be_eq_obj *eqo) 
	return num;

}



static int event_handle(struct be_eq_obj *eqo)

{

	bool rearm = false;

	int num = events_get(eqo);



	/* Deal with any spurious interrupts that come without events */

	if (!num)

		rearm = true;



	if (num || msix_enabled(eqo->adapter))

		be_eq_notify(eqo->adapter, eqo->q.id, rearm, true, num);



	if (num)

		napi_schedule(&eqo->napi);



	return num;

}



/* Leaves the EQ is disarmed state */

static void be_eq_clean(struct be_eq_obj *eqo)

{
@@ -2014,15 +1996,23 @@ static int be_rx_cqs_create(struct be_adapter *adapter) 


static irqreturn_t be_intx(int irq, void *dev)

{

	struct be_adapter *adapter = dev;

	int num_evts;

	struct be_eq_obj *eqo = dev;

	struct be_adapter *adapter = eqo->adapter;

	int num_evts = 0;



	/* With INTx only one EQ is used */

	num_evts = event_handle(&adapter->eq_obj[0]);

	if (num_evts)

	/* On Lancer, clear-intr bit of the EQ DB does not work.

	 * INTx is de-asserted only on notifying num evts.

	 */

	if (lancer_chip(adapter))

		num_evts = events_get(eqo);



	/* The EQ-notify may not de-assert INTx rightaway, causing

	 * the ISR to be invoked again. So, return HANDLED even when

	 * num_evts is zero.

	 */

	be_eq_notify(adapter, eqo->q.id, false, true, num_evts);

	napi_schedule(&eqo->napi);

	return IRQ_HANDLED;

	else

		return IRQ_NONE;

}



static irqreturn_t be_msix(int irq, void *dev)
@@ -2342,10 +2332,10 @@ static int be_irq_register(struct be_adapter *adapter) 
			return status;

	}



	/* INTx */

	/* INTx: only the first EQ is used */

	netdev->irq = adapter->pdev->irq;

	status = request_irq(netdev->irq, be_intx, IRQF_SHARED, netdev->name,

			adapter);

			     &adapter->eq_obj[0]);

	if (status) {

		dev_err(&adapter->pdev->dev,

			"INTx request IRQ failed - err %d\n", status);
@@ -2367,7 +2357,7 @@ static void be_irq_unregister(struct be_adapter *adapter) 


	/* INTx */

	if (!msix_enabled(adapter)) {

		free_irq(netdev->irq, adapter);

		free_irq(netdev->irq, &adapter->eq_obj[0]);

		goto done;

	}
@@ -3023,8 +3013,10 @@ static void be_netpoll(struct net_device *netdev) 
	struct be_eq_obj *eqo;

	int i;



	for_all_evt_queues(adapter, eqo, i)

		event_handle(eqo);

	for_all_evt_queues(adapter, eqo, i) {

		be_eq_notify(eqo->adapter, eqo->q.id, false, true, 0);

		napi_schedule(&eqo->napi);

	}



	return;

}