diff mbox series

[net,1/3] ibmvnic: avoid calling napi_disable() twice

Message ID 20210414074616.11299-2-lijunp213@gmail.com (mailing list archive)
State Accepted
Commit 0775ebc4cf8554bdcd2c212669a0868ab68df5c0
Delegated to: Netdev Maintainers
Headers show
Series ibmvnic: correctly call NAPI APIs | expand

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netdev/cc_maintainers fail 2 blamed authors not CCed: davem@davemloft.net nfont@linux.vnet.ibm.com; 10 maintainers not CCed: drt@linux.ibm.com paulus@samba.org sukadev@linux.ibm.com benh@kernel.crashing.org linuxppc-dev@lists.ozlabs.org mpe@ellerman.id.au ljp@linux.ibm.com davem@davemloft.net nfont@linux.vnet.ibm.com kuba@kernel.org
netdev/source_inline success Was 0 now: 0
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netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/kdoc success Errors and warnings before: 3 this patch: 3
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netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 9 lines checked
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Commit Message

Lijun Pan April 14, 2021, 7:46 a.m. UTC
__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 <tlfalcon@linux.ibm.com>
Signed-off-by: Lijun Pan <lijunp213@gmail.com>
---
 drivers/net/ethernet/ibm/ibmvnic.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)
diff mbox series

Patch

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;
 	}