net: hns3: Fix for deadlock problem occurring when unregistering ae_algo

When hnae3_unregister_ae_algo is called by PF, pci_disable_sriov is
called. And then, hns3_remove is called by VF. We get deadlocked in
this case.

Since VF pci device is dependent on PF pci device, When PF pci device
is removed, VF pci device must be removed. Also, To solve the deadlock
problem, VF pci device should be removed before PF pci device is removed.

This patch moves pci_enable/disable_sriov from hclge to hns3 to solve
the deadlock problem.

Also, we do not need to return EPROBE_DEFER in hnae3_register_ae_dev,
because SRIOV is no longer enabled in the context calling
hnae3_register_ae_dev. Mutex_trylock can be replaced with mutex_lock.

Fixes: 424eb834a9be ("net: hns3: Unified HNS3 {VF|PF} Ethernet Driver for hip08 SoC")
Signed-off-by: Fuyun Liang <liangfuyun1@huawei.com>
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 10 deletions

diff --git a/drivers/net/ethernet/hisilicon/hns3/hnae3.c b/drivers/net/ethernet/hisilicon/hns3/hnae3.c
index 02145f2de820..1686cebead96 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hnae3.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hnae3.c
@@ -196,17 +196,9 @@ int hnae3_register_ae_dev(struct hnae3_ae_dev *ae_dev)
 	const struct pci_device_id *id;
 	struct hnae3_ae_algo *ae_algo;
 	struct hnae3_client *client;
-	int ret = 0, lock_acquired;
+	int ret = 0;
 
-	/* we can get deadlocked if SRIOV is being enabled in context to probe
-	 * and probe gets called again in same context. This can happen when
-	 * pci_enable_sriov() is called to create VFs from PF probes context.
-	 * Therefore, for simplicity uniformly defering further probing in all
-	 * cases where we detect contention.
-	 */
-	lock_acquired = mutex_trylock(&hnae3_common_lock);
-	if (!lock_acquired)
-		return -EPROBE_DEFER;
+	mutex_lock(&hnae3_common_lock);
 
 	list_add_tail(&ae_dev->node, &hnae3_ae_dev_list);