i40e: Fix ethtool coalesce settings

This patch fixes the i40e_set_coalesce function to allow 0 as a disable
value.  Also, added message to user about invalid value and provides valid
range.

Change-ID: I6c9ff11a9861f2045bd543745a3d132999ffbbd8
Signed-off-by: NCarolyn Wyborny <carolyn.wyborny@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/i40e/i40e.h

@@ -617,6 +617,7 @@ static inline void i40e_dbg_init(void) {}
 static inline void i40e_dbg_exit(void) {}
 #endif /* CONFIG_DEBUG_FS*/
 void i40e_irq_dynamic_enable(struct i40e_vsi *vsi, int vector);
+void i40e_irq_dynamic_disable(struct i40e_vsi *vsi, int vector);
 void i40e_irq_dynamic_disable_icr0(struct i40e_pf *pf);
 void i40e_irq_dynamic_enable_icr0(struct i40e_pf *pf);
 int i40e_ioctl(struct net_device *netdev, struct ifreq *ifr, int cmd);

drivers/net/ethernet/intel/i40e/i40e_ethtool.c

@@ -1105,17 +1105,36 @@ static int i40e_set_coalesce(struct net_device *netdev,
 	if (ec->tx_max_coalesced_frames_irq || ec->rx_max_coalesced_frames_irq)
 		vsi->work_limit = ec->tx_max_coalesced_frames_irq;
 
+	vector = vsi->base_vector;
 	if ((ec->rx_coalesce_usecs >= (I40E_MIN_ITR << 1)) &&
-	    (ec->rx_coalesce_usecs <= (I40E_MAX_ITR << 1)))
+	    (ec->rx_coalesce_usecs <= (I40E_MAX_ITR << 1))) {
 		vsi->rx_itr_setting = ec->rx_coalesce_usecs;
-	else
+	} else if (ec->rx_coalesce_usecs == 0) {
+		vsi->rx_itr_setting = ec->rx_coalesce_usecs;
+		i40e_irq_dynamic_disable(vsi, vector);
+		if (ec->use_adaptive_rx_coalesce)
+			netif_info(pf, drv, netdev,
+				   "Rx-secs=0, need to disable adaptive-Rx for a complete disable\n");
+	} else {
+		netif_info(pf, drv, netdev,
+			   "Invalid value, Rx-usecs range is 0, 8-8160\n");
 		return -EINVAL;
+	}
 
 	if ((ec->tx_coalesce_usecs >= (I40E_MIN_ITR << 1)) &&
-	    (ec->tx_coalesce_usecs <= (I40E_MAX_ITR << 1)))
+	    (ec->tx_coalesce_usecs <= (I40E_MAX_ITR << 1))) {
 		vsi->tx_itr_setting = ec->tx_coalesce_usecs;
-	else
+	} else if (ec->tx_coalesce_usecs == 0) {
+		vsi->tx_itr_setting = ec->tx_coalesce_usecs;
+		i40e_irq_dynamic_disable(vsi, vector);
+		if (ec->use_adaptive_tx_coalesce)
+			netif_info(pf, drv, netdev,
+				   "Tx-secs=0, need to disable adaptive-Tx for a complete disable\n");
+	} else {
+		netif_info(pf, drv, netdev,
+			   "Invalid value, Tx-usecs range is 0, 8-8160\n");
 		return -EINVAL;
+	}
 
 	if (ec->use_adaptive_rx_coalesce)
 		vsi->rx_itr_setting |= I40E_ITR_DYNAMIC;
@@ -1127,7 +1146,6 @@ static int i40e_set_coalesce(struct net_device *netdev,
 	else
 		vsi->tx_itr_setting &= ~I40E_ITR_DYNAMIC;
 
-	vector = vsi->base_vector;
 	for (i = 0; i < vsi->num_q_vectors; i++, vector++) {
 		q_vector = vsi->q_vectors[i];
 		q_vector->rx.itr = ITR_TO_REG(vsi->rx_itr_setting);

drivers/net/ethernet/intel/i40e/i40e_main.c

@@ -2767,6 +2767,22 @@ void i40e_irq_dynamic_enable(struct i40e_vsi *vsi, int vector)
 	/* skip the flush */
 }
 
+/**
+ * i40e_irq_dynamic_disable - Disable default interrupt generation settings
+ * @vsi: pointer to a vsi
+ * @vector: enable a particular Hw Interrupt vector
+ **/
+void i40e_irq_dynamic_disable(struct i40e_vsi *vsi, int vector)
+{
+	struct i40e_pf *pf = vsi->back;
+	struct i40e_hw *hw = &pf->hw;
+	u32 val;
+
+	val = I40E_ITR_NONE << I40E_PFINT_DYN_CTLN_ITR_INDX_SHIFT;
+	wr32(hw, I40E_PFINT_DYN_CTLN(vector - 1), val);
+	i40e_flush(hw);
+}
+
 /**
  * i40e_msix_clean_rings - MSIX mode Interrupt Handler
  * @irq: interrupt number