From 0775ebc4cf8554bdcd2c212669a0868ab68df5c0 Mon Sep 17 00:00:00 2001 From: Lijun Pan Date: Wed, 14 Apr 2021 02:46:14 -0500 Subject: [PATCH 1/3] ibmvnic: avoid calling napi_disable() twice __ibmvnic_open calls napi_disable without checking whether NAPI polling has already been disabled or not. This could cause napi_disable being called twice, which could generate deadlock. For example, the first napi_disable will spin until NAPI_STATE_SCHED is cleared by napi_complete_done, then set it again. When napi_disable is called the second time, it will loop infinitely because no dev->poll will be running to clear NAPI_STATE_SCHED. To prevent above scenario from happening, call ibmvnic_napi_disable() which checks if napi is disabled or not before calling napi_disable. Fixes: bfc32f297337 ("ibmvnic: Move resource initialization to its own routine") Suggested-by: Thomas Falcon Signed-off-by: Lijun Pan Signed-off-by: David S. Miller --- drivers/net/ethernet/ibm/ibmvnic.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c index 110a0d0eaabb..2d27f8aa0d4b 100644 --- a/drivers/net/ethernet/ibm/ibmvnic.c +++ b/drivers/net/ethernet/ibm/ibmvnic.c @@ -1149,8 +1149,7 @@ static int __ibmvnic_open(struct net_device *netdev) rc = set_link_state(adapter, IBMVNIC_LOGICAL_LNK_UP); if (rc) { - for (i = 0; i < adapter->req_rx_queues; i++) - napi_disable(&adapter->napi[i]); + ibmvnic_napi_disable(adapter); release_resources(adapter); return rc; } From d3a6abccbd272aea7dc2c6f984bb5a2c11278e44 Mon Sep 17 00:00:00 2001 From: Lijun Pan Date: Wed, 14 Apr 2021 02:46:15 -0500 Subject: [PATCH 2/3] ibmvnic: remove duplicate napi_schedule call in do_reset function During adapter reset, do_reset/do_hard_reset calls ibmvnic_open(), which will calls napi_schedule if previous state is VNIC_CLOSED (i.e, the reset case, and "ifconfig down" case). So there is no need for do_reset to call napi_schedule again at the end of the function though napi_schedule will neglect the request if napi is already scheduled. Fixes: ed651a10875f ("ibmvnic: Updated reset handling") Signed-off-by: Lijun Pan Signed-off-by: David S. Miller --- drivers/net/ethernet/ibm/ibmvnic.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c index 2d27f8aa0d4b..f4bd63216672 100644 --- a/drivers/net/ethernet/ibm/ibmvnic.c +++ b/drivers/net/ethernet/ibm/ibmvnic.c @@ -1921,7 +1921,7 @@ static int do_reset(struct ibmvnic_adapter *adapter, u64 old_num_rx_queues, old_num_tx_queues; u64 old_num_rx_slots, old_num_tx_slots; struct net_device *netdev = adapter->netdev; - int i, rc; + int rc; netdev_dbg(adapter->netdev, "[S:%d FOP:%d] Reset reason %d, reset_state %d\n", @@ -2110,10 +2110,6 @@ static int do_reset(struct ibmvnic_adapter *adapter, /* refresh device's multicast list */ ibmvnic_set_multi(netdev); - /* kick napi */ - for (i = 0; i < adapter->req_rx_queues; i++) - napi_schedule(&adapter->napi[i]); - if (adapter->reset_reason == VNIC_RESET_FAILOVER || adapter->reset_reason == VNIC_RESET_MOBILITY) __netdev_notify_peers(netdev); From 7c451f3ef676c805a4b77a743a01a5c21a250a73 Mon Sep 17 00:00:00 2001 From: Lijun Pan Date: Wed, 14 Apr 2021 02:46:16 -0500 Subject: [PATCH 3/3] ibmvnic: remove duplicate napi_schedule call in open function Remove the unnecessary napi_schedule() call in __ibmvnic_open() since interrupt_rx() calls napi_schedule_prep/__napi_schedule during every receive interrupt. Fixes: ed651a10875f ("ibmvnic: Updated reset handling") Signed-off-by: Lijun Pan Signed-off-by: David S. Miller --- drivers/net/ethernet/ibm/ibmvnic.c | 5 ----- 1 file changed, 5 deletions(-) diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c index f4bd63216672..ffb2a91750c7 100644 --- a/drivers/net/ethernet/ibm/ibmvnic.c +++ b/drivers/net/ethernet/ibm/ibmvnic.c @@ -1156,11 +1156,6 @@ static int __ibmvnic_open(struct net_device *netdev) netif_tx_start_all_queues(netdev); - if (prev_state == VNIC_CLOSED) { - for (i = 0; i < adapter->req_rx_queues; i++) - napi_schedule(&adapter->napi[i]); - } - adapter->state = VNIC_OPEN; return rc; }