[PATCH net v3 1/2] i40e: drop udp_tunnel_get_rx_info() call from i40e_open()

[mheib@redhat.com]

From: Mohammad Heib <mheib@redhat.com>

The i40e driver calls udp_tunnel_get_rx_info() during i40e_open().
This is redundant because UDP tunnel RX offload state is preserved
across device down/up cycles. The udp_tunnel core handles
synchronization automatically when required.

Furthermore, recent changes in the udp_tunnel infrastructure require
querying RX info while holding the udp_tunnel lock. Calling it
directly from the ndo_open path violates this requirement,
triggering the following lockdep warning:

  Call Trace:
   <TASK>
   ? __udp_tunnel_nic_assert_locked+0x39/0x40 [udp_tunnel]
   i40e_open+0x135/0x14f [i40e]
   __dev_open+0x121/0x2e0
   __dev_change_flags+0x227/0x270
   dev_change_flags+0x3d/0xb0
   devinet_ioctl+0x56f/0x860
   sock_do_ioctl+0x7b/0x130
   __x64_sys_ioctl+0x91/0xd0
   do_syscall_64+0x90/0x170
   ...
   </TASK>

Remove the redundant and unsafe call to udp_tunnel_get_rx_info() from
i40e_open() resolve the locking violation.

Fixes: 1ead7501094c ("udp_tunnel: remove rtnl_lock dependency")
Signed-off-by: Mohammad Heib <mheib@redhat.com>
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>
---
 drivers/net/ethernet/intel/i40e/i40e_main.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 0b1cc0481027..d3bc3207054f 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -9030,7 +9030,6 @@ int i40e_open(struct net_device *netdev)
 						       TCP_FLAG_FIN |
 						       TCP_FLAG_CWR) >> 16);
 	wr32(&pf->hw, I40E_GLLAN_TSOMSK_L, be32_to_cpu(TCP_FLAG_CWR) >> 16);
-	udp_tunnel_get_rx_info(netdev);
 
 	return 0;
 }
-- 
2.52.0