[PATCH net 3/4] iavf: Fix TC config comparison with existing adapter TC config

[Tony Nguyen <anthony.l.nguyen@intel.com>]

From: Sudheer Mogilappagari <sudheer.mogilappagari@intel.com>

Same number of TCs doesn't imply that underlying TC configs are
same. The config could be different due to difference in number
of queues in each TC. Add utility function to determine if TC
configs are same.

Fixes: d5b33d024496 ("i40evf: add ndo_setup_tc callback to i40evf")
Signed-off-by: Sudheer Mogilappagari <sudheer.mogilappagari@intel.com>
Tested-by: Mineri Bhange <minerix.bhange@intel.com> (A Contingent Worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/iavf/iavf_main.c | 30 ++++++++++++++++++++-
 1 file changed, 29 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/iavf/iavf_main.c b/drivers/net/ethernet/intel/iavf/iavf_main.c
index ef2440f3abf8..166832a4213a 100644
--- a/drivers/net/ethernet/intel/iavf/iavf_main.c
+++ b/drivers/net/ethernet/intel/iavf/iavf_main.c
@@ -3502,6 +3502,34 @@ static void iavf_del_all_cloud_filters(struct iavf_adapter *adapter)
 	spin_unlock_bh(&adapter->cloud_filter_list_lock);
 }
 
+/**
+ * iavf_is_tc_config_same - Compare the mqprio TC config with the
+ * TC config already configured on this adapter.
+ * @adapter: board private structure
+ * @mqprio_qopt: TC config received from kernel.
+ *
+ * This function compares the TC config received from the kernel
+ * with the config already configured on the adapter.
+ *
+ * Return: True if configuration is same, false otherwise.
+ **/
+static bool iavf_is_tc_config_same(struct iavf_adapter *adapter,
+				   struct tc_mqprio_qopt *mqprio_qopt)
+{
+	struct virtchnl_channel_info *ch = &adapter->ch_config.ch_info[0];
+	int i;
+
+	if (adapter->num_tc != mqprio_qopt->num_tc)
+		return false;
+
+	for (i = 0; i < adapter->num_tc; i++) {
+		if (ch[i].count != mqprio_qopt->count[i] ||
+		    ch[i].offset != mqprio_qopt->offset[i])
+			return false;
+	}
+	return true;
+}
+
 /**
  * __iavf_setup_tc - configure multiple traffic classes
  * @netdev: network interface device structure
@@ -3559,7 +3587,7 @@ static int __iavf_setup_tc(struct net_device *netdev, void *type_data)
 		if (ret)
 			return ret;
 		/* Return if same TC config is requested */
-		if (adapter->num_tc == num_tc)
+		if (iavf_is_tc_config_same(adapter, &mqprio_qopt->qopt))
 			return 0;
 		adapter->num_tc = num_tc;
 
-- 
2.41.0