From b4dfd326c29c241c2bb8463167217eb2438b7c3d Mon Sep 17 00:00:00 2001 From: Alistair Popple Date: Wed, 30 Oct 2013 10:50:37 +1100 Subject: ibm emac: Don't call napi_complete if napi_reschedule failed This patch fixes a bug which would trigger the BUG_ON() at net/core/dev.c:4156. It was found that this was due to continuing processing in the current poll call even when the call to napi_reschedule failed, indicating the device was already on the polling list. This resulted in an extra call to napi_complete which triggered the BUG_ON(). This patch ensures that we only contine processing rotting packets in the current mal_poll call if we are not already on the polling list. Signed-off-by: Alistair Popple Signed-off-by: David S. Miller --- drivers/net/ethernet/ibm/emac/mal.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) (limited to 'drivers/net/ethernet/ibm') diff --git a/drivers/net/ethernet/ibm/emac/mal.c b/drivers/net/ethernet/ibm/emac/mal.c index dac564c25440..909f9b6698b5 100644 --- a/drivers/net/ethernet/ibm/emac/mal.c +++ b/drivers/net/ethernet/ibm/emac/mal.c @@ -442,15 +442,11 @@ static int mal_poll(struct napi_struct *napi, int budget) if (unlikely(mc->ops->peek_rx(mc->dev) || test_bit(MAL_COMMAC_RX_STOPPED, &mc->flags))) { MAL_DBG2(mal, "rotting packet" NL); - if (napi_reschedule(napi)) - mal_disable_eob_irq(mal); - else - MAL_DBG2(mal, "already in poll list" NL); - - if (budget > 0) - goto again; - else + if (!napi_reschedule(napi)) goto more_work; + + mal_disable_eob_irq(mal); + goto again; } mc->ops->poll_tx(mc->dev); } -- cgit v1.2.3 From 32663b8b8948cc05f812ab82c1c7db2db3ddf717 Mon Sep 17 00:00:00 2001 From: Alistair Popple Date: Wed, 30 Oct 2013 10:50:38 +1100 Subject: ibm emac: Fix locking for enable/disable eob irq Calls to mal_enable_eob_irq perform a read-write-modify of a dcr to enable device irqs which is protected by a spin lock. However calls to mal_disable_eob_irq do not take the corresponding lock. This patch resolves the problem by ensuring that calls to mal_disable_eob_irq also take the lock. Signed-off-by: Alistair Popple Signed-off-by: David S. Miller --- drivers/net/ethernet/ibm/emac/mal.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'drivers/net/ethernet/ibm') diff --git a/drivers/net/ethernet/ibm/emac/mal.c b/drivers/net/ethernet/ibm/emac/mal.c index 909f9b6698b5..e7847510eda2 100644 --- a/drivers/net/ethernet/ibm/emac/mal.c +++ b/drivers/net/ethernet/ibm/emac/mal.c @@ -263,7 +263,9 @@ static inline void mal_schedule_poll(struct mal_instance *mal) { if (likely(napi_schedule_prep(&mal->napi))) { MAL_DBG2(mal, "schedule_poll" NL); + spin_lock(&mal->lock); mal_disable_eob_irq(mal); + spin_unlock(&mal->lock); __napi_schedule(&mal->napi); } else MAL_DBG2(mal, "already in poll" NL); @@ -445,7 +447,9 @@ static int mal_poll(struct napi_struct *napi, int budget) if (!napi_reschedule(napi)) goto more_work; + spin_lock_irqsave(&mal->lock, flags); mal_disable_eob_irq(mal); + spin_unlock_irqrestore(&mal->lock, flags); goto again; } mc->ops->poll_tx(mc->dev); -- cgit v1.2.3