[PATCH v1 1/5] idpf: address an rtnl lock splat in tx timeout recovery path

[Manoj Vishwanathan]

Adopt the same pattern as in other places in the code to take the rtnl
lock during hard resets.
Tested the patch by injecting tx timeout in IDPF , observe that idpf
recovers and IDPF comes back reachable

Without this patch causes there is a splat:
[  270.145214] WARNING: CPU:  PID:  at net/sched/sch_generic.c:534 dev_watchdog

Signed-off-by: Manoj Vishwanathan <manojvishy@xxxxxxxxxx>
---
 drivers/net/ethernet/intel/idpf/idpf_txrx.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/idpf/idpf_txrx.c b/drivers/net/ethernet/intel/idpf/idpf_txrx.c
index af2879f03b8d..3c01be90fa75 100644
--- a/drivers/net/ethernet/intel/idpf/idpf_txrx.c
+++ b/drivers/net/ethernet/intel/idpf/idpf_txrx.c
@@ -4328,14 +4328,26 @@ int idpf_vport_intr_init(struct idpf_vport *vport)
 {
 	char *int_name;
 	int err;
+	bool hr_reset_in_prog;
 
 	err = idpf_vport_intr_init_vec_idx(vport);
 	if (err)
 		return err;
 
 	idpf_vport_intr_map_vector_to_qs(vport);
+	/**
+	 * If we're in normal up path, the stack already takes the
+	 * rtnl_lock for us, however, if we're doing up as a part of a
+	 * hard reset, we'll need to take the lock ourself before
+	 * touching the netdev.
+	 */
+	hr_reset_in_prog = test_bit(IDPF_HR_RESET_IN_PROG,
+				    vport->adapter->flags);
+	if (hr_reset_in_prog)
+		rtnl_lock();
 	idpf_vport_intr_napi_add_all(vport);
-
+	if (hr_reset_in_prog)
+		rtnl_unlock();
 	err = vport->adapter->dev_ops.reg_ops.intr_reg_init(vport);
 	if (err)
 		goto unroll_vectors_alloc;
-- 
2.46.0.76.ge559c4bf1a-goog