ice: Report what the user set for coalesce [tx|rx]-usecs

Currently if the user sets an odd value for [tx|rx]-usecs we align the
value because the hardware only understands ITR values in multiples of
2. This seems misleading because we are essentially telling the user
that the ITR value is odd, when in fact we have changed it internally.
Fix this by reporting that setting odd ITR values is not allowed.

Also, while making changes to ice_set_rc_coalesce() I noticed a bit of
code/error duplication. Make the necessary changes to remove the
duplication.
Signed-off-by: Brett Creeley <brett.creeley@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/ice/ice_ethtool.c

@@ -3253,25 +3253,25 @@ static int
 ice_set_rc_coalesce(enum ice_container_type c_type, struct ethtool_coalesce *ec,
 		    struct ice_ring_container *rc, struct ice_vsi *vsi)
 {
+	const char *c_type_str = (c_type == ICE_RX_CONTAINER) ? "rx" : "tx";
+	u32 use_adaptive_coalesce, coalesce_usecs;
 	struct ice_pf *pf = vsi->back;
 	u16 itr_setting;
 
 	if (!rc->ring)
 		return -EINVAL;
 
-	itr_setting = rc->itr_setting & ~ICE_ITR_DYNAMIC;
-
 	switch (c_type) {
 	case ICE_RX_CONTAINER:
 		if (ec->rx_coalesce_usecs_high > ICE_MAX_INTRL ||
 		    (ec->rx_coalesce_usecs_high &&
 		     ec->rx_coalesce_usecs_high < pf->hw.intrl_gran)) {
 			netdev_info(vsi->netdev,
-				    "Invalid value, rx-usecs-high valid values are 0 (disabled), %d-%d\n",
-				    pf->hw.intrl_gran, ICE_MAX_INTRL);
+				    "Invalid value, %s-usecs-high valid values are 0 (disabled), %d-%d\n",
+				    c_type_str, pf->hw.intrl_gran,
+				    ICE_MAX_INTRL);
 			return -EINVAL;
 		}
-
 		if (ec->rx_coalesce_usecs_high != rc->ring->q_vector->intrl) {
 			rc->ring->q_vector->intrl = ec->rx_coalesce_usecs_high;
 			wr32(&pf->hw, GLINT_RATE(rc->ring->q_vector->reg_idx),
@@ -3279,58 +3279,58 @@ ice_set_rc_coalesce(enum ice_container_type c_type, struct ethtool_coalesce *ec,
 						   pf->hw.intrl_gran));
 		}
 
-		if (ec->rx_coalesce_usecs != itr_setting &&
-		    ec->use_adaptive_rx_coalesce) {
+		use_adaptive_coalesce = ec->use_adaptive_rx_coalesce;
+		coalesce_usecs = ec->rx_coalesce_usecs;
+
+		break;
+	case ICE_TX_CONTAINER:
+		if (ec->tx_coalesce_usecs_high) {
 			netdev_info(vsi->netdev,
-				    "Rx interrupt throttling cannot be changed if adaptive-rx is enabled\n");
+				    "setting %s-usecs-high is not supported\n",
+				    c_type_str);
 			return -EINVAL;
 		}
 
-		if (ec->rx_coalesce_usecs > ICE_ITR_MAX) {
-			netdev_info(vsi->netdev,
-				    "Invalid value, rx-usecs range is 0-%d\n",
-				   ICE_ITR_MAX);
+		use_adaptive_coalesce = ec->use_adaptive_tx_coalesce;
+		coalesce_usecs = ec->tx_coalesce_usecs;
+
+		break;
+	default:
+		dev_dbg(&pf->pdev->dev, "Invalid container type %d\n", c_type);
 		return -EINVAL;
 	}
 
-		if (ec->use_adaptive_rx_coalesce) {
-			rc->itr_setting |= ICE_ITR_DYNAMIC;
-		} else {
-			rc->itr_setting = ITR_REG_ALIGN(ec->rx_coalesce_usecs);
-			rc->target_itr = ITR_TO_REG(rc->itr_setting);
-		}
-		break;
-	case ICE_TX_CONTAINER:
-		if (ec->tx_coalesce_usecs_high) {
+	itr_setting = rc->itr_setting & ~ICE_ITR_DYNAMIC;
+	if (coalesce_usecs != itr_setting && use_adaptive_coalesce) {
 		netdev_info(vsi->netdev,
-				    "setting tx-usecs-high is not supported\n");
+			    "%s interrupt throttling cannot be changed if adaptive-%s is enabled\n",
+			    c_type_str, c_type_str);
 		return -EINVAL;
 	}
 
-		if (ec->tx_coalesce_usecs != itr_setting &&
-		    ec->use_adaptive_tx_coalesce) {
+	if (coalesce_usecs > ICE_ITR_MAX) {
 		netdev_info(vsi->netdev,
-				    "Tx interrupt throttling cannot be changed if adaptive-tx is enabled\n");
+			    "Invalid value, %s-usecs range is 0-%d\n",
+			    c_type_str, ICE_ITR_MAX);
 		return -EINVAL;
 	}
 
-		if (ec->tx_coalesce_usecs > ICE_ITR_MAX) {
+	/* hardware only supports an ITR granularity of 2us */
+	if (coalesce_usecs % 2 != 0) {
 		netdev_info(vsi->netdev,
-				    "Invalid value, tx-usecs range is 0-%d\n",
-				   ICE_ITR_MAX);
+			    "Invalid value, %s-usecs must be even\n",
+			    c_type_str);
 		return -EINVAL;
 	}
 
-		if (ec->use_adaptive_tx_coalesce) {
+	if (use_adaptive_coalesce) {
 		rc->itr_setting |= ICE_ITR_DYNAMIC;
 	} else {
-			rc->itr_setting = ITR_REG_ALIGN(ec->tx_coalesce_usecs);
-			rc->target_itr = ITR_TO_REG(rc->itr_setting);
-		}
-		break;
-	default:
-		dev_dbg(&pf->pdev->dev, "Invalid container type %d\n", c_type);
-		return -EINVAL;
+		/* store user facing value how it was set */
+		rc->itr_setting = coalesce_usecs;
+		/* set to static and convert to value HW understands */
+		rc->target_itr =
+			ITR_TO_REG(ITR_REG_ALIGN(rc->itr_setting));
 	}
 
 	return 0;